Light emitting apparatus and method for manufacturing the same

ABSTRACT

The purpose of the invention is to improve reliability of a light emitting apparatus comprising a TFT and organic light emitting elements.  
     The light emitting apparatus according to the invention having a thin film transistor and a light emitting element, comprises; a first inorganic insulation layer on the lower surface of a semiconductor layer, a second inorganic insulation layer on the upper surface of agate electrode, a first organic insulation layer on the second inorganic insulation layer, a third inorganic insulation layer on the first organic insulation layer, a wiring layer extending on the third inorganic insulation layer, a second organic insulation layer overlapped with the end of the wiring layer and having an inclination angle of 35 to 45 degrees, a fourth inorganic insulation layer formed on the upper surface and side surface of the second organic insulation layer and having an opening over the wiring layer, a cathode layer formed in contact with the wiring layer and having side end overlapped with the fourth inorganic insulation layer, and an organic compound layer formed in contact with the cathode layer and the fourth inorganic insulation layer and comprising light emitting material, and an anode layer formed in contact with the organic compound layer comprising the light emitting material, wherein the third inorganic insulation layer and the fourth inorganic insulation layer are formed with silicon nitride or aluminum nitride.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a light emitting apparatuscomprising a light emitting element which emit fluorescent light orphosphorescent light. In particular, the invention relates to a lightemitting apparatus comprising an active element such as insulation gatetype transistor or a thin film transistor, and a light emitting elementcoupled thereto.

[0003] 2. Description of the Related Art

[0004] A typical display apparatus utilizing liquid crystal uses a backlight or a front light for displaying images. A liquid crystal displayapparatus is employed as an image displaying unit in variouselectronics, but suffers a problem that it has a narrow angled field ofview. On the contrary, a display which uses light emitting elementsproviding electro-luminescence as a display unit has a wider-angledfield of view as well as high level of visual recognition. Theseadvantages make the electro-luminescent display prospective for the nextgeneration.

[0005] In a light emitting element utilizing the electro-luminescence,electrons injected from a cathode and positive holes injected from ananode couple on a layer comprising light emitting material to formexcitons. Light is generated by the energy released when the excitonsmove back to the ground state. There are two types ofelectro-luminescence, i.e., fluorescent light and phosphorescent light,each which are considered as light emitted from the excitons in asinglet state (fluorescent light), and light emitted from the excitonsin a triplet state (phosphorescent light), respectively. The luminancefrom electro-luminescence ranges from thousands cd/m² to tens ofthousands cd/m², which makes it possible in principle to adopt theelectro-luminescence light emitting elements in a variety ofapplications including a display apparatus.

[0006] An example of a combination of a thin-film transistor(hereinafter referred to as “TFT”) and a light emitting element isdisclosed in the Japanese Patent Laid-Open No. JP-A-8-241047. In theconstruction disclosed in this JP-A-8-241047, an organicelectro-luminescence layer is formed over a TFT comprisingpolycrystalline silicon, via an insulation film comprising silicondioxide. A passivasion layer having a tapered end on the anode ispositioned under the organic electro-luminescence layer. The cathode ismade from a material with a work function of 4 eV or less. An example ofan applicable material is an alloy of metal such as silver or aluminum,and magnesium.

[0007] Problem To Be Solved

[0008] Known methods for manufacturing the organic electro-luminescencelayer include vacuum evaporation, printing, and spin coating. However,it is difficult to form determined patterns on the organicelectro-luminescence layer by photolithography technique as used in thesemiconductor element manufacturing. In order to arrange the lightemitting elements in a matrix to make a display screen, a specialconstruction is necessary in which each pixel is partitioned withinsulation material, as disclosed in the above JP-A-8-241047.

[0009] In the first place, an organic compound used for the lightemitting elements, and an alkali metal or an alkali earth metal used foran electrode are degraded by reactions with water and oxygen. Thisprevents practical application of the light emitting apparatuscomprising the light emitting elements.

[0010] The organic light emitting element deteriorates due to followingsix factors; (1) change in the chemical characteristics of the organiccompound (2) change in the structure, or deterioration by fusion, of theorganic compounds by heat generated at operating, (3) destruction ofinsulation due to macro-level defect, (4) deterioration of the interfacebetween the electrodes, or the electrode and the organic compound layercomprising the light emitting element, (5) deterioration caused by thechange in bonding state or crystallization of the organic compound dueto amorphous form, and (6) irreversible destruction caused by stress ordistortion due to the structure of the elements.

[0011] The deterioration by the factor (1) is caused by chemical changeincurred by excitation, or gas which is corrosive against the organiccompounds or moisture. The deterioration by the factor (2) and (3) iscaused by the operation of the organic light emitting element. Heat isinevitably generated when current in the element is converted into Jouleheat. When the organic compound has low melting point or glasstransition temperature, the electric field concentrate around pinholesor cracks and dielectric breakdowns occur. The deterioration by thefactors (4) and (5) is inevitable even when the element is stored atambient temperature. The deterioration by the factor (4) is known asdark spots, which are generated by the oxidation of the cathode or thereaction to moisture. For deterioration by the factor (5), all theorganic compounds used in the organic light emitting element areamorphous, so that they will be inevitably crystallized in a long periodby heat for example. Almost no organic compound can keep its amorphousstructure for a long time. For deterioration by the factor (6), a defectsuch as a crack or a break of the coating due to distortion may developby the difference in thermal expansion coefficient between components.Furthermore, the crack or the break may lead to a progressive defectsuch as dark spots.

[0012] The advance in sealing techniques has fairly mitigated theproblem of dark spots. However in practice, the deterioration is causedby two or more of the above factors, which makes it difficult to takeeffective preventive measure. In typical sealing method, the organiclight emitting element formed over a substrate is sealed with sealant,and drying agent such as barium oxide is applied in the spaces.Unfortunately, conventional preventive measures have failed to suppressthe deterioration of the light emitting apparatus to an acceptablelevel.

SUMMARY OF THE INVENTION

[0013] The purpose of the present invention is to solve the aboveproblems in order to improve the reliability of a light emittingapparatus comprising TFTs and organic light emitting elements.

[0014] For this purpose, according to the present invention, a lightemitting apparatus with pixels consisting of electrically connected TFTsand light emitting elements has a construction wherein the lightemitting elements are formed by laminating an anode layer, a cathodelayer, and an interposed layer containing light emitting material,surrounding the upper surface, the lower surface and the side surface ofthe light emitting element with an inorganic insulation layer, and theanode layer, the cathode layer and the layer containing light emittingmaterial respectively contact with the surrounding inorganic insulationlayer. The inorganic insulation layer is formed of silicon nitride oroxynitride of silicon such as a silicon nitride film or a siliconoxynitride film, or, nitride or oxynitride of aluminum such as aluminumnitride or aluminum oxynitride. More preferably, the silicon nitridefilm formed by radio frequency sputtering (RF sputtering) with frequencyranging from 13.56 MHz to 120 MHz and having silicon as a target isapplied.

[0015] The silicon nitride film manufactured by the RF sputtering hasimproved effect of blocking the external impurities and an effect ofsuppressing the deterioration of the light emitting element bysatisfying one of the following conditions; (1) a silicon nitride filmwith etching rate of 9 nm/min or less (preferably, 0.5 to 3.5 nm/min orless), (2) hydrogen concentration of 1×10²¹ atoms/cm⁻³ or less(preferably 5×10²⁰ atoms/cm³ or less), (3) hydrogen concentration of1×10²¹ atoms/cm³ or less (preferably 5×10²⁰ atoms/cm³ or less), andoxygen concentration from 5×10¹⁸ to 5×10²¹ atoms/cm³ (preferably 1×10¹⁹to 1×10²¹ atoms/cm³), (4) etching rate of 9 nm/min or less (preferably,0.5 to 3.5 nm/min or less), and hydrogen concentration of 1×10²¹atoms/cm³ or less (preferably 5×10²⁰ atoms/cm³ or less), or (5) etchingrate of 9 nm/min or less (preferably, 0.5 to 3.5 nm/min or less),hydrogen concentration of 1×10²¹ atoms/cm³ or less (preferably 5×10²⁶atoms/cm³ or less), and oxygen concentration from 5×10¹⁸ to 5×10²¹atoms/cm³ (preferably 1×10¹⁹ to 1×10²¹ atoms/cm³).

[0016] In a construction wherein a display screen has light emittingelements arranged in matrix, the most preferable construction of aninsulation layer to partition the each pixel comprises a positive-typeor a negative-type photosensitive organic resin material and has acurvature radius of 0.2 to 2 μm or continuously varying curvatureradiuses within the above range at the end of the patterns, and atapered surface with an inclination angle from 10 to 75 degrees,preferably from 35 to 45 degrees. The construction of a pixel in thelight emitting apparatus according to the invention can mitigate thestress on the electrode ends of the pixel and suppress the deteriorationof the light emitting element, by forming an insulation layer whichcovers ends of the individual electrode (either anode or cathode) ofeach pixel connecting to the TFT to partition each pixel, and by forminga layer containing the light emitting material, and one of the anodelayer or the cathode layer, from over the pixel electrode to over theinsulation layer.

[0017] The construction of a light emitting apparatus according to theinvention will be described below.

[0018] A light emitting apparatus comprising a TFT having asemiconductor layer, a gate insulation film and a gate electrode, and alight emitting element having an organic compound layer containing lightemitting material between a cathode layer and an anode layer, comprises,

[0019] a first inorganic insulation layer under the semiconductor layer,

[0020] a second inorganic insulation layer on the gate electrode,

[0021] a first organic insulation layer on the second inorganicinsulation layer,

[0022] a third inorganic insulation layer on the first organicinsulation layer,

[0023] a wiring layer extending on the third inorganic insulation layer,

[0024] a second organic insulation layer overlapping with the end of thewiring layer, the second organic insulation layer having an inclinationangle of 35 to 45 degrees,

[0025] a fourth inorganic insulation layer formed on the upper surfaceand the side surface of the second organic insulation layer, the fourthinorganic insulation layer having an opening over the wiring layer,

[0026] a cathode layer formed in contact with the wiring layer andhaving an end overlapping with the fourth inorganic insulation layer,

[0027] an organic compound layer formed in contact with the cathodelayer and the fourth inorganic insulation layer, the organic compoundlayer containing the light emitting material, and

[0028] an anode layer formed in contact with the organic compound layercontaining the light emitting material,

[0029] wherein;

[0030] the third inorganic insulation layer and the fourth inorganicinsulation layer comprise silicon nitride or aluminum nitride.

[0031] A light emitting apparatus comprising a pixel section having aTFT having a semiconductor layer, a gate insulation film and a gateelectrode, and a light emitting element including an organic compoundlayer containing light emitting material between an anode layer and acathode layer, and a driving circuit section formed from a thin filmtransistor having a semiconductor layer, a gate insulation film and agate electrode, the driving circuit section being formed in theperipheral region of the pixel section, comprises;

[0032] a first inorganic insulation layer under the semiconductor layer,

[0033] a second inorganic insulation layer on the gate electrode,

[0034] a first organic insulation layer on the second inorganicinsulation layer,

[0035] a third inorganic insulation layer on the first organicinsulation layer,

[0036] a wiring layer extending on the third inorganic insulation layer,

[0037] a second organic insulation layer overlapping with the end of thewiring layer, the second organic insulation layer having an inclinationangle of 35 to 45 degrees,

[0038] a fourth inorganic insulation layer formed on the upper surfaceand the side surface of the second organic insulation layer, the fourthinorganic insulation layer having an opening over the wiring layer,

[0039] a cathode layer formed in contact with the wiring layer, thecathode layer having an end overlapping with the fourth inorganicinsulation layer,

[0040] an organic compound layer formed in contact with the cathodelayer and the fourth inorganic insulation layer, the organic compoundlayer containing the light emitting material, and,

[0041] an anode layer formed in contact with the organic compound layercontaining the light emitting material,

[0042] wherein;

[0043] the third inorganic insulation layer and the fourth inorganicinsulation layer comprise silicon nitride or aluminum nitride,

[0044] seal patterns are formed on the fourth inorganic insulationlayer, and

[0045] some or all of the seal patterns overlap with the driving circuitsection.

[0046] The cathode layer may have the fifth inorganic insulation layerthereon, which is formed of nitride of silicon or aluminum.

[0047] The third to the fifth inorganic insulation layers have the abovementioned etching characteristics, and hydrogen concentration and oxygenconcentration in the above range. By reducing the density of N—H bond,Si—H bond and the Si—O bond, the construction according to the inventioncan improve thermal stability of a film and make a fine film.

[0048] A light emitting apparatus comprising a pixel section having aTFT having a semiconductor layer, a gate insulation film and a gateelectrode, and a light emitting element including an organic compoundlayer containing light emitting material between an anode layer and acathode layer, and a driving circuit section formed from a TFT having asemiconductor layer, a gate insulation film and a gate electrode, thedriving circuit section being formed in the peripheral region of thepixel section, wherein;

[0049] a barrier layer formed from an organic insulation layer on thepixel section extends over the driving circuit section,

[0050] an inorganic insulation layer comprising silicon nitride oraluminum nitride is formed on the upper surface and the side surface ofthe barrier layer,

[0051] seal patterns are formed on the inorganic insulation layer,

[0052] some or all of the seal patterns overlap with the driving circuitsection, and

[0053] a connection between the anode layer and the wiring formed underthe anode layer is provided inside of the seal patterns.

[0054] A light emitting apparatus comprising a pixel section having afirst TFT having a semiconductor layer, a gate insulation film and agate electrode, and a light emitting element including an organiccompound layer containing light emitting material between an anode layerand a cathode layer, and a driving circuit section formed from a secondTFT having a semiconductor layer, a gate insulation film and a gateelectrode, the driving circuit section being formed in the peripheralregion of the pixel section, wherein;

[0055] a barrier layer formed from an organic insulation layer on thepixel section extends over the driving circuit section,

[0056] an inorganic insulation layer comprising silicon nitride oraluminum nitride is formed on the upper surface and the side surface ofthe barrier layer,

[0057] seal patterns are formed on the inorganic insulation layer,

[0058] the first TFT is formed inside of the seal patterns,

[0059] all or some of the second TFT overlap with the seal patterns,and,

[0060] a connection between the anode layer and the wiring formed underthe anode layer is provided inside of the seal patterns.

[0061] The inorganic insulation layer comprises silicon nitridemanufactured by the RF sputtering method, and has the above mentionedetching characteristics, and hydrogen concentration and oxygenconcentration in the above range.

[0062] The another aspect of the invention provides a method tomanufacture a light emitting apparatus, as described below.

[0063] A method for manufacturing a light emitting apparatus comprisinga pixel section having a TFT having a semiconductor layer, a gateinsulation film and a gate electrode, and a light emitting elementincluding an organic compound layer containing light emitting materialbetween an anode layer and a cathode layer, and a driving circuitsection formed from a thin film transistor having a semiconductor layer,a gate insulation film and a gate electrode, the driving circuit sectionbeing formed in the peripheral region of the pixel section, comprisessteps of;

[0064] forming a first inorganic insulation layer on a substrate,

[0065] forming a semiconductor layer comprising crystalline silicon onthe first inorganic insulation layer,

[0066] forming a gate insulation film on the semiconductor layer and agate electrode on the gate insulation film,

[0067] forming a second inorganic insulation layer on the gateelectrode,

[0068] forming a first organic insulation layer on the second inorganicinsulation layer,

[0069] forming a third inorganic insulation layer on the second organicinsulation layer,

[0070] forming a wiring layer in contact with the third inorganicinsulation layer,

[0071] forming a second organic insulation layer overlapping with theend of the wiring layer, the second organic insulation layer having aninclination angle of 35 to 45 degrees,

[0072] forming a fourth inorganic insulation layer on the upper surfaceand side surface of the second organic insulation layer, the fourthinorganic insulation layer having an opening over the wiring layer,

[0073] forming a cathode layer in contact with the wiring layer, thecathode layer having an end overlapping with the fourth insulationlayer,

[0074] forming an organic compound layer containing the light emittingmaterial in contact with the cathode layer and the fourth inorganicinsulation layer, and,

[0075] forming an anode layer in contact with the organic compound layercontaining the light emitting material, wherein,

[0076] the third inorganic insulation layer and the fourth inorganicinsulation layer comprise silicon nitride or aluminum nitride formed byRF sputtering method.

[0077] A method for manufacturing a light emitting apparatus comprisinga pixel section having a TFT having a semiconductor layer, a gateinsulation film and a gate electrode, and a light emitting elementincluding an organic compound layer containing light emitting materialbetween an anode layer and a cathode layer, and a driving circuitsection formed from a TFT having a semiconductor layer, a gateinsulation film and a gate electrode, the driving circuit section beingformed in the peripheral region of the pixel section, comprises stepsof;

[0078] forming a first inorganic insulation layer on a substrate,

[0079] forming a semiconductor layer comprising crystalline silicon onthe first inorganic insulation layer,

[0080] forming a gate insulation film on the semiconductor layer and agate electrode on the gate insulation film,

[0081] forming a second inorganic insulation layer on the gateelectrode,

[0082] forming a first organic insulation layer on the second inorganicinsulation layer,

[0083] forming a third inorganic insulation layer on the second organicinsulation layer,

[0084] forming a wiring layer in contact with the third inorganicinsulation layer,

[0085] forming a second organic insulation layer overlapping with theend of the wiring layer, the second organic insulation layer having aninclination angle of 35 to 45 degrees,

[0086] forming a fourth inorganic insulation layer on the upper surfaceand side surface of the second organic insulation layer, the fourthinorganic insulation layer having an opening over the wiring layer,

[0087] forming a cathode layer in contact with the wiring layer, thecathode layer having an end overlapping with the fourth insulationlayer,

[0088] forming an organic compound layer containing the light emittingmaterial formed in contact with the cathode layer and the fourthinorganic insulation layer,

[0089] forming an anode layer in contact with the organic compound layercontaining the light emitting material,

[0090] forming seal patterns on the fourth insulation layer at aposition in which some or all of the seal patterns overlap with thedriving circuit section, and,

[0091] adhering a sealing plate in alignment with the seal patterns,

[0092] wherein,

[0093] the third inorganic insulation layer and the fourth inorganicinsulation layer comprise silicon nitride or aluminum nitride formed byRF sputtering method.

[0094] In the above construction according to the invention, the thirdand the fourth inorganic insulation layers comprise silicon nitride bythe RF sputtering method using only nitrogen as sputtering gas andhaving silicon as a target. The third inorganic insulation layer isformed after formation of the first organic insulation layer, by heatingand dehydrating under reduced pressure, while the reduced pressure ismaintained. The fourth inorganic insulation layer is formed afterformation of the second organic insulation layer, by heating anddehydrating under reduced pressure, while the reduced pressure ismaintained.

[0095] The light emitting apparatus herein refers to the apparatus whichuses electro-luminescence for emitting light, in general. The lightemitting apparatus includes a TFT substrate in which circuitry is formedfrom TFT on a substrate for light emission, an EL panel whichincorporates the light emitting elements formed withelectro-luminescence material on a TFT substrate, and an EL module whichincorporates external circuitry into an EL panel. The light emittingapparatus according to the invention can be incorporated in a variety ofelectronics such as a mobile telephone, a personal computer and atelevision receiver.

BRIEF DESCRIPTION OF THE DRAWING

[0096]FIG. 1 is a cross-sectional view which illustrates theconstruction of the light emitting apparatus according to the invention.

[0097]FIG. 2 is a top view which illustrates the construction of thepixel section of the light emitting apparatus according to theinvention.

[0098]FIG. 3 is a cross-sectional view which illustrates theconstruction of the pixel section of the light emitting apparatusaccording to the invention.

[0099]FIG. 4 is another cross-sectional view which illustrates theconstruction of the pixel section of the light emitting apparatusaccording to the invention.

[0100]FIG. 5 is an outside view of a substrate comprising components ofthe light emitting apparatus according to the invention.

[0101]FIG. 6 is a view which illustrates a substrate constituting alight emitting apparatus formed on a mother glass, and its separation.

[0102]FIGS. 7A to 7C show a construction of the input terminal in thelight emitting apparatus according to the invention.

[0103]FIGS. 8A to 8D are cross-sectional views which illustratemanufacturing processes of the light emitting apparatus according to theinvention.

[0104]FIGS. 9A to 9C are cross-sectional views which illustratemanufacturing processes of the light emitting apparatus according to theinvention.

[0105]FIGS. 10A to 10C are cross-sectional views which illustratemanufacturing processes of the light emitting apparatus according to theinvention.

[0106]FIGS. 11A and 11B are cross-sectional views which illustratemanufacturing processes of the light emitting apparatus according to theinvention.

[0107]FIG. 12 is a top view which illustrates manufacturing processes ofthe light emitting apparatus according to the invention.

[0108]FIG. 13 is a top view which illustrates manufacturing processes ofthe light emitting apparatus according to the invention.

[0109]FIG. 14 is a cross-sectional view which illustrates a constructionof the light emitting apparatus according to the invention.

[0110]FIG. 15 is a top view which illustrates a construction of thepixel section of the light emitting apparatus according to theinvention.

[0111]FIG. 16 is a top view which illustrates a construction of thepixel section of the light emitting apparatus according to theinvention.

[0112]FIG. 17 is a circuit diagram equivalent to a pixel.

[0113]FIG. 18 shows an example of a process to manufacture semiconductorlayers to be adopted in the TFT constituting the light emittingapparatus according to the invention.

[0114]FIG. 19 shows an example of a process to manufacture semiconductorlayers to be adopted in the TFT constituting the light emittingapparatus according to the invention.

[0115]FIGS. 20A to 20C show an example of a process to manufacturesemiconductor layers to be adopted in the TFT constituting the lightemitting apparatus according to the invention.

[0116]FIG. 21 shows an example of a process to manufacture semiconductorlayers to be adopted in the TFT constituting the light emittingapparatus according to the invention.

[0117]FIGS. 22A to 22G are views which show applications of theinvention.

[0118]FIGS. 23A and 23B show one construction of the EL module.

[0119]FIG. 24 is a graph which shows SIMS measurement data (secondaryion mass spectrometry) of the silicon nitride film.

[0120]FIG. 25 is a graph which shows FT-IR measurement data of thesilicon nitride film.

[0121]FIG. 26 is a graph which shows measurement of the transmittance ofthe silicon nitride film.

[0122]FIG. 27 is a graph which shows the C-V characteristics before andafter the BT stress test of the MOS construction.

[0123]FIGS. 28A and 28B are graphs which show the C-V characteristicsbefore and after the BT stress test of the MOS construction.

[0124]FIGS. 29A and 29B are views which illustrate the MOS construction.

[0125]FIG. 30 is a view which illustrates a sputtering apparatus.

[0126]FIGS. 31A and 31B are cross-sectional views which illustrate theconstruction of the pixel section of the light emitting apparatusaccording to the invention.

[0127]FIGS. 32A and 32B are cross-sectional views which illustrate theconstruction of the pixel section of the light emitting apparatusaccording to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0128] The embodiments of the invention will be described with referenceto the accompanied drawings. Common components among several drawingshave same reference numerals.

[0129]FIG. 1 shows a construction of a light emitting apparatus of anactive matrix driving method according to the present invention. TheTFTs are provided in a pixel section 302 and a driving circuit section301 formed around the pixel section 302. Either amorphous silicon,polysilicon, or single crystal silicon is applicable for thesemiconductor layer which forms the channel forming region of the TFT.For switching purpose, the TFT may be formed with organic semiconductor.

[0130] The substrate 101 comprises a glass substrate or an organic resinsubstrate. The organic resin has lighter weight than the glass, which isadvantageous to reduce the weight of the light emitting apparatus as awhole. Organic resin such as polyimide, polyethylene terephthalate(PET), polyethylene naphthalate (PEN), polyether sulfone (PES), andaramid is applicable to manufacture the light emitting apparatus.Borosilicate glass which is known as no-alkali glass containing lessamount of alkali metal element is preferred to be used as a glasssubstrate. The thickness of the glass substrate may be 0.5 to 1.1 mm,however, if it is necessary to reduce the weight of the apparatus, thethickness should be reduced. It is desirable to employ a glass materialwith small specific density such as 2.37 g/cm³ to furthermore reduce theweight.

[0131] In the construction shown in FIG. 1, a n-channel type TFT 303 anda p-channel type TFT 304 are formed in the driving circuit section 301,and a first TFT 305 and a fourth TFT 306 formed with n-channel type TFTare formed in the pixel section 302. The fourth TFT 306 connects to acathode 126 of a light emitting element 309.

[0132] These TFT comprises semiconductor layers 103 to 106, a gateinsulation film 108, and gate electrodes 110 to 113 on a first inorganicinsulation layer 102 formed of silicon nitride or silicon oxynitride. Asecond inorganic insulation layer 114 formed of silicon nitride orsilicon oxynitride containing hydrogen is formed on the gate electrode.The second inorganic insulation layer in combination with the firstinorganic insulation layer 102 serves as a protective film whichprevents contamination of the semiconductor layers caused by diffusionof impurities such as moisture or metal into the semiconductor layer.

[0133] A first organic insulation layer 115 of 0.5 to 1 μm thicknessformed of one of polyimid, polyamide, polyimidamide, acrylic, BCB(benzocyclobutene) is formed as a planarizing layer on the secondinorganic insulation layer 114. The first organic insulation layer 115is formed by spin coating one of the above organic compounds, thenapplying calcination. The organic insulation material is hygroscopic andabsorbs and occludes moisture. When the occluded moisture is released,oxygen is supplied to the organic compounds included in the lightemitting element formed over the organic insulation layer, whichdeteriorates the organic light emitting element. To prevent theocclusion and the release of moisture, a third inorganic insulationlayer 116 of 50 to 200 nm thickness is formed on the first organicinsulation layer 115. The third inorganic insulation layer 116 must be afine film in order to adhere to the underlining layer more securely toprovide barrier. The layer 116 is formed preferably by the sputtering ofan inorganic insulation material selected from silicon nitride, siliconoxynitride, aluminum oxynitride and aluminum nitride. Wirings 117 to 125are formed after the formation of the third inorganic insulation layer116.

[0134] The light emitting element 309 is formed on an anode layer 131,the cathode layer 126 comprising alkali metal or alkali earth metal, andan interposing organic compound layer 130 containing a light emittingmaterial. The organic compound layer 130 containing the light emittingmaterial is formed by laminating one or more layers. Each layer is namedaccording to its purpose and function; a positive hole injection layer,a positive hole transferring layer, a light emitting layer, an electronstransferring layer and an electrons injection layer. These layers can beformed of low molecular weight organic compounds, middle molecularweight organic compounds, high molecular weight organic compounds, orcombination of two of the above compounds appropriately. Also, a mixedlayer comprising mixture of the electron transferring material and thepositive hole transferring material, or a mixed connection forming mixedregion between the interface of them can be made.

[0135] This organic light emitting element 309 is formed on the thirdinorganic insulation layer 116. The light emitting apparatus having aconstruction to emit light in the direction opposite to the substrate101 causes the cathode layer 126 of the light emitting element 309 tocontact to the wiring 123 formed on the third inorganic insulation layer116. The cathode layer 126 is formed of an alkali metal or an alkaliearth metal having smaller work function, such as magnesium (Mg),lithium (Li) or calcium (Ca). Preferably, an electrode comprising MgAg(a mixture of Mg and Ag with ratio of 10:1) may be used. Other materialssuitable to the elctrode include MgAgAl, LiAl and LiFAl. The combinationof fluoride of an alkali metal an or alkali earth metal, and a lowresistance metal such as alminum can be used, as well.

[0136] A second organic insulation layer (partition layer) 128 whichseparates each pixel is formed of one of polyimide, polyamide,polyimideamide, acrylic and benzocyclobutene (BCB). Thermosettingmaterial or photo-curing material is applicable. The second organicinsulation layer (partition layer) 128 is formed by applying the one ofthe above organic insulation material with thickness of 0.5 to 2 μm tocover all surface. Then, an opening fitting to the cathode layer 126 isformed. At this time, the opening is formed so as to cover the end ofthe wiring 123 and the inclination angle on its side is 35 to 45degrees. The second organic insulation layer (partition layer) 128extends not only over the pixel section 302 but also over the drivingcircuit section 301 and covers the wiring 117 to 124, thus, it alsoserves as an interlayer insulation film between layers.

[0137] The organic insulation material is hygroscopic and absorbs andoccludes moisture. When the occluded moisture is released, the moistureis supplied to the organic compounds of the light emitting element 309,which deteriorates the organic light emitting element. To prevent theocclusion and the release of moisture, a fourth inorganic insulationlayer 129 of 10 to 100 nm thickness is formed on the second organicinsulation layer 128. The fourth inorganic insulation layer 129 isformed of an inorganic insulation material comprising nitrides.Particularly, it is formed with an inorganic insulation materialselected from silicon nitride, aluminum nitride and aluminum oxynitride.The fourth inorganic insulation layer 129 is formed so as to cover theupper surface and side surface of the second organic insulation layer128, and its end overlapping with the wiring 123 is tapered.

[0138] The anode layer 131 is formed across a plurality of pixels as acommon electrode, and connects to the wiring 120 at a connection region310 positioned outside of the pixel section 302 or between the pixelsection 302 and the driving circuit section 301, then leads to anexternal terminal. ITO layer (indium oxide, tin) layer is formed as theanode layer 131. ITO may be added with zinc oxide or gallium forplanarizing, or reducing the resistance.

[0139] On the anode layer 131, a fifth inorganic insulation layer 132may be formed of one of silicon nitride, diamond-like-carbon (DLC),aluminum oxynitride, aluminum oxide or aluminum nitride. It is knownthat the DLC film has high gas barrier characteristic against oxygen,CO, CO₂ and H₂O. It is desirable to form the fifth inorganic insulationlayer 132 in succession after the formation of the anodes 131 withoutexposing the substrate to the atmosphere. A buffer layer made of siliconnitride may be provided under the fifth inorganic insulation layer 132in order to improve adhesion.

[0140] Although not shown in the figure, a sixth inorganic insulationlayer of 0.5 to 5 nm thickness which allows flow of a tunnel current maybe formed between the cathode layer 126 and the organic compound layer130 containing light emitting material. The sixth inorganic insulationlayer has an effect to prevent short circuit caused by any irregularityon the surface of the anode, and an effect to prevent alkali metal usedfor the cathode, or the like, from diffusing to the lower layer.

[0141] The second organic insulation layer 128 formed over the pixelsection 302 extends to the driving circuit section 301, and sealpatterns 133 are formed on the fourth inorganic insulation layer 129formed on the second organic insulation layer 128. Some or all of theseal patterns 133 may overlap with the driving circuit section 301 andthe wiring 117 which connects the driving circuit section 301 and theinput terminal, which reduces the area of the frame region (peripheralregion of the pixel section) of the light emitting apparatus. The lightfrom the light emitting element 309 is emitted through this sealingplate.

[0142] A sealing plate 134 is secured via the sealing patterns 133. Anorganic resin including polyimide, polyethylene terephthalate (PET),polyethylene naphthalate (PEN), polyethersulfone (PES) and aramid aswell as a glass substrate can be used for the sealing plate 134. Thesealing plate made of an organic resin may be flexible and have 30 to120 μm thickness. This prevents scratch on the surface of the sealingplate. The surface of the sealing plate may be coated with an inorganicinsulation material such as DLC and silicon nitride as a gas barrierlayer. One exemplary material for the seal patterns is epoxy adhesive.The side surface of the seal patterns may be coated with a filmcomprising inorganic insulation material, which prevents vapor frompenetrating from the side surface.

[0143] In FIG. 1, the first TFT 305 has a multi-gate construction, andprovided with a light doped drain (LDD) to reduce the off current. A LDDoverlapping with the gate electrode is provided on the fourth TFT 306. ATFT made of poly-crystalline silicon is prone to deteriorate caused by ahot-carrier effect because it has a high operating rate. Therefore, asshown in FIG. 1, it is highly advantageous to form TFTs having differentconstruction for different function in the pixel (switching TFT withsufficiently low off current and current control TFT durable to hotcarrier injection), in order to manufacture a display apparatus havinghigh reliability and good displaying performance (high operatingperformance).

[0144] The top view of one pixel in the pixel section provided with theabove TFT is shown in FIG. 2. In order to illustrate the arrangement ofeach TFT clearly, the patterns of the light emitting element 309, thesecond organic insulation layer 128 and the fourth inorganic insulationlayer 129 are not shown in FIG. 2. One pixel contains the first TFT 305,a second TFT 311, a third TFT 312, the fourth TFT 306 and a capacitysection 307. FIG. 17 schematically shows a circuit equivalent to theconstruction shown in FIG. 2. FIG. 1 shows the cross section across theline A-A′ of FIG. 2. FIG. 3 shows the cross section across the lineB-B′, and FIG. 4 shows the cross section across the line C-C′, of FIG.2.

[0145] One exemplary construction of the second organic insulation layer128 and the fourth inorganic insulation layer 129 in the pixel sectionis shown in FIG. 15, in which both of them cover the periphery of thecathode layer 126. In another exemplary construction shown in FIG. 16,the second organic insulation later 128 may cover only two sides of thecathode layer 126, while the fourth inorganic insulation layer 129 maycover all sides of the cathode layer 126.

[0146] Although not shown in FIG. 1, the driving circuit section 301 hasdifferent circuitry for the gate signal driving circuit and the datasignal driving circuit. The wirings 118 and 119 are connected to then-channel type TFT 303 and the p-channel type TFT 304, respectively, andthese TFTs, in turn, can be used to form a shift register, a latchcircuit or a buffer circuit.

[0147] An input terminal 308 is formed from a wiring formed from thesame layer as the gate electrode, or a wiring formed on the thirdinorganic insulation layer 116. FIG. 1 shows an example of the inputterminal 308 formed from the same layer as the gate electrode, that is,the input terminal 308 is formed from conducting layers 109 and 127. Theconducting layer 127 is formed of oxide conductive material, at the timewhen the anode layer 131 is formed. In practice, the part exposed to thesurface is covered with the oxide conductive material to prevent theincrease of surface resistance due to oxidation. FIG. 7 is a detailedillustration of the input terminal 308. FIG. 7A shows the top view, andFIGS. 7B and 7C show cross-sectional views across the line D-D′ andE-E′, respectively. The reference numerals in FIG. 7 are in common withthose in FIG. 1.

[0148] As shown in FIG. 1, the first inorganic insulation layer 102 andthe second inorganic insulation layer 114 are formed so as to sandwichthe semiconductor layers 105 and 106. On the other hand, the organiclight emitting element 309 is surrounded by the third inorganicinsulation layer 116, the fifth inorganic insulation layer 132 and thefourth inorganic insulation layer 129. In other words, the semiconductorlayers of the TFT and light emitting elements are coated with theinorganic insulation layers, respectively. The inorganic insulationlayers are made from films of silicon nitride or silicon oxynitride,which forms a barrier against vapor and ionic impurities.

[0149] The possible source of an alkali metal such as sodium whichcontaminates the first TFT 305 and the fourth TFT 306 includes thesubstrate 101 and the organic light emitting element 309. In order toprevent the contamination from them, the first TFT 305 and the fourthTFT 306 are surrounded by the first inorganic insulation layer 102 andthe second inorganic insulation layer 114. As the organic light emittingelement 309 suffers the severest damage from oxygen and moisture, thethird inorganic insulation layer 116, the fourth inorganic insulationlayer 129, and the fifth inorganic insulation layer 132 are formed withinorganic insulation materials to prevent the contamination by oxygen ormoisture. Also, these inorganic insulation layer serves to prevent thealkali metal element of the organic light emitting element 309 fromdiffusing to other sections.

[0150]FIG. 5 shows an outside view of a substrate comprising componentsof the light emitting apparatus illustrated in FIGS. 1 to 4. Thesubstrate 101 comprises the pixel section 302, a gate signal drivingcircuits 301 a and 302 b, a data signal driving circuit 301 c, theconnection 310 to the anode layer, the input/output terminal 308 andwiring or a group of wirings 117. The seal patterns 133 are provided sothat the part or all of the patterns 133 overlap with the gate signaldriving circuits 301 a and 301 b, data signal driving circuit 301 c andthe wiring or the group of wirings 117 which connects these drivingcircuit sections to the input terminal, in order to reduce the area ofthe frame region (peripheral of the pixel section) of the light emittingapparatus. The anode layer formed of ITO may have high resistivity,therefore, although FIG. 5 shows only one connection 310 to the anodelayer, more than one connections 310 may be provided on the other regionaround the pixel section 302.

[0151] As shown in FIG. 6, a plurality of the substrates (101 a to 110d) having above construction are provided on a mother glass 201, andseparated along cutting lines 202 after the formation of one of thefourth inorganic insulation layer, the cathode layer, the fifthinorganic insulation layer or the sealing plate. The substrates areseparated with a diamond cutter or a laser cutter. In order to make theseparating process easier, the third to the fifth inorganic insulationlayers and the first and the second organic insulation layers arepreferably removed along the cutting lines 202.

[0152] As described, a TFT and alight emitting element are combined toform a pixel section to complete a light emitting apparatus. In thelight emitting apparatus thus manufactured, driving circuits can beformed on the same substrate by using TFTs as the pixel section. Asshown in FIG. 1, by surrounding the upper surface and the lower surfaceof the semiconductor film, the gate insulation film and the gateelectrode, which are major components of a TFT, with blocking layers andthe protective films comprising silicon nitride or silicon oxynitride,this construction prevents these components from being contaminated byan alkali metal and an organic material. The organic light emittingelement, in turn, contains the alkali metal in part, and surrounded by aprotective film comprising one of silicon nitride, silicon oxynitride,or DLC, and a gas barrier layer comprising an insulation film mainlyconsisting of silicon nitride or carbon, so that this constructionprevents the penetration of oxygen or moisture from the outside.

[0153] The film comprising silicon nitride used for the inorganicinsulation layers in this embodiment (silicon nitride film) is a highlyfine film formed by the RF sputtering, according to the processingconditions shown in the table 1 (A typical example is illustrated).“RFSP-SiN” in the table indicates a silicon nitride film formed by theRF sputtering. “T/S” is the distance between the target and thesubstrate. TABLE 1 RFSP-SiN processing condition representativeprocessing condition example comments gas N₂ or (noble gas)/N₂ Ar/N₂each purity is 4 N or more gas flow ratio N₂: 30˜100%, Ar:N₂ = noble gasmay be noble gas: 0˜70% 20:20 (sccm) introduced as gas for heating formthe backside of a substrate pressure (Pa) 0.1˜1.5 0.8 flequency 13˜4013.56 (MHz) power (W/cm²)  5˜20 16.5 substrate RT (Room 200 temperatureTemperature) (° C.)   ˜350 target material carved out Si (1˜10 Ωcm)material of single crystalline Si ingot T/S (mm)  40˜200 60back-pressure 1 × 10⁻³ or less 3 × 10⁻⁵ using turbo- (Pa) (preferablymolecular pump  3 × 10⁻⁵ or less) or cryopump

[0154] Ar is introduced as sputtering gas to be sprayed on the backsurface of the substrate to heat the same. The sprayed Ar is ultimatelymixed with N₂ for sputtering. The values shown in the table 1 forforming a film are only exemplary values. As long as the physicalparameters of the resulting SiN film fall in the range of the physicalparameters shown in the table 4 (shown later), these conditions can bemodified appropriately by the operator.

[0155] Next, a schematic view of a sputtering apparatus used to form asilicon nitride film by the above RF sputtering will be shown in FIG.30. In FIG. 30, 30 is a chamber wall, 31 is a movable magnet for formingmagnetic field, 32 is a single crystal silicon target, 33 is aprotective shutter, 34 is a substrate to be processed, 36 a and 36 b areheaters, 37 is a substrate chuck device, 38 is an antitack plate and 39is a valve (conductance valve or main valve). The chamber wall 30 isprovided with gas intake tubes 40 and 41 which introduce N₂ (or mix gasof N₂ and inert gas), and inert gas, respectively.

[0156] Table 2 shows conditions to form a silicon nitride film formed bythe conventional plasma CVD method, for reference. “PCVD-SiN” in thetable refers to a silicon nitride film formed by the plasma CVD method.TABLE 2 plasma CVD condition PCVD-SiN gas SiH₄/NH₃/N₂/H₂ gas flow ratio(sccm) SiH4:NH3:N2:H2 = 30:240:300:60 pressure (Pa) 159 frequency (MHz)13.56 power (W/cm²) 0.35 substrate temperature (° C.) 325

[0157] Table 3 shows the the representative values of physicalcharacteristics (physical parameters) of the silicon nitride film formedunder the conditions in the table 1, and that formed under theconditions in the table 2. The differences between “RFSP-SiN (No. 1)”and “RFSP-SiN (No. 2)” are attributable to the difference between thefilm forming apparatuses, and do not impair the function of a siliconnitride film as a barrier film according to the invention. The internalstress may be compressive or tensile, and the sign of the numericalvalue changes accordingly, but the table shows only the absolute value.TABLE 3 comparison between representative SiN physical parameters SiNprepared by the condition SiN prepared by the referring to conditionreferring to the the preparing preparing condition in condition inTable. 1 Table. 2 RFSP-SiN RFSP-SiN PCVD-SiN parameter (No. 1) (No. 2)film comments specific inductive 7.02˜9.30 ←  ˜7 capacity refractiveindex 1.91˜2.13 ← 2.0˜2.1 Wavelength of irradiated light is 632.8 nminternal stress 4.17 × 10⁸ ← 9.11 × 10⁸ (dyn/cm²) etching rate 0.77˜1.311˜8.6  ˜30 LAL500, (nm/min) 20° C. Si concentration 37.3 51.5 35.0 RBS(atomic %) N concentration 55.9 48.5 45.0 RBS (atomic %) H concentration   4 × 10²⁰ —    1 × 10²² SIMS (atoms/cm³) O concentration    8 × 10²⁰ —   3 × 10¹⁸ SIMS (stoms/cm³) C concentration    1 × 10¹⁹ —    4 × 10¹⁷SIMS (atoms/cm³)

[0158] As shown in the table 3, the common characteristics in theRFSP-SiN (No. 1) and the RFSP-SiN (No. 2) are lower etching rate (theetching rate of the etching with LAL 500 at 20° C., ditto), and lowerhydrogen concentration compared to that of the PCVD-SiN film. “LAL500”is the “LAL500 SA buffered hydrofluoric acid” which is solution ofNH₄HF₂ (7.13%) and NH₄F (15.4%), manufactured by Hashimoto Kasei Co.,Ltd. The absolute value of the internal stress is lower than that of thesilicon nitride film formed by the plasma CVD method.

[0159] Next, various physical parameters of the silicon nitride filmformed by the inventors under the conditions in table 1 are summarizedin the table 4. TABLE 4 SiN physical parameters used in the presentinvention parameter SiN film used in the present invention commentsspecific inductive 7.0˜9.5 capacity (preferably 7.3˜7.7) refractiveindex 1.85˜2.20 Wavelength  (preferably 1.90˜2.15) of irradiated lightis 632.8 nm internal stress 2 × 10¹⁰ or less (dyn/cm²) (preferably 5 ×10⁸ or less)  etch rate 9 or less LAL500, (nm/min) (preferably 0.5˜3.5)20° C. Si concentration 35˜55 RBS (atomic %) (preferably 37˜52)   Nconcentration 45˜60 RBS (atomic %) (preferably 48˜56)   H concentration1 × 10²¹ or less SIMS (atoms/cm³) (preferably 5 × 10²⁰ or less) Oconcentration 5 × 10¹⁸˜5 × 10²¹ SIMS (atoms/cm³) (preferably 1 × 10¹⁹˜1× 10²¹) C concentration 1 × 10¹⁸˜5 × 10¹⁹ SIMS (atoms/cm³) (preferably 1× 10¹⁸˜2 × 10¹⁹)

[0160] The results of the SIMS (secondary ion mass spectrometry) andFT-IR, and the transmittance, of the above silicon nitride film, areshown in FIGS. 24, 25 and 26, respectively. FIG. 26 also shows thesilicon nitride film formed under the conditions of the table 2. Thetransmission factor is almost comparable to that of the conventionalPCVD-SiN film.

[0161] The silicon nitride film used as an inorganic insulation layeraccording to the invention preferably satisfies the parameters shown inthe table 4. That is, the inorganic insulation layer preferablysatisfies one of the following conditions; (1) a silicon nitride filmwith etching rate of 9 nm/min or less (preferably, 0.5 to 3.5 nm/min orless), (2) hydrogen concentration of 1×10²¹ atoms/cm³ or less(preferably 5×10²⁰ atoms/cm³ or less), (3) hydrogen concentration of1×10²¹ atoms/cm³ or less (preferably 5×10²⁰ atoms/cm³ or less), andoxygen concentration of from 5×10¹⁸ to 5×10²¹ atoms/cm³ (preferably1×10¹⁹ to 1×10²¹ atoms/cm³), (4) etching rate of 9 nm/min or less(preferably, 0.5 to 3.5 nm/min or less), and hydrogen concentration of1×10²¹ atoms/cm³ or less (preferably 5×10²⁰ atoms/cm³ or less), and (5)etching rate of 9 nm/min or less (preferably, 0.5 to 3.5 nm/min orless), hydrogen concentration of 1×10²¹ atoms/cm³ or less (preferably5×10²⁰ atoms/cm³ or less), and oxygen concentration of from 5×10¹⁸ to5×10²¹ atoms/cm³ (preferably 1×10¹⁹ to 1×10²¹ atoms/cm³).

[0162] The absolute value of the internal stress may be 2×10¹⁰ dyn/cm²or less, preferably 5×10⁹ dyn/cm² or less, and more preferably 5×10⁸dyn/cm² or less. The smaller internal stress can reduce the differenceof the energy level between the films, as well as prevent the film frompeeling by the internal stress.

[0163] The silicon nitride film formed under condition shown in thetable 1 according to this embodiment has a distinct blocking effectagainst the elements belonging to Group 1 and Group 2 in the periodictable such as Na and Li, and can effectively suppress the diffusion ofthese mobile ions. For example, a metal film made of aluminum with 0.2to 1.5 wt % (preferably, 0.5 to 1.0 wt %) lithium added is preferred fora cathode layer of this embodiment in terms of various physicalcharacteristics including charge injection characteristic. However, whenusing this type of metal film, the lithium may diffuse and damage theperformance of the transistor. To prevent this damage, the presentembodiment completely protects the transistor with inorganic insulationlayers, so that the lithium would not diffuse to the transistor.

[0164] This is shown in the data in FIGS. 27 to 29. FIG. 27 is a diagramthat shows the change in the C-V characteristic before and after the BTstress test of the MOS structure which has a silicon nitride film(PCVD-SiN film) formed under conditions of the table 2 as a dielectric.The construction of the sample is shown in FIG. 29A, and the effect ofthe diffusion of the lithium can be determined by using Al—Li (lithiumadded aluminum) electrode as the surface electrode. As shown in FIG. 27,the BT stress test reveals that the C-V characteristic is significantlyshifted, which indicates that the lithium diffused from the surfaceelectrode has a substantial effect.

[0165]FIGS. 28A and 28B show the C-V characteristic before and after theBT stress test of the MOS structure which has a silicon nitride filmformed under conditions of the table 1 as a dielectrics. The differencein the tests of FIG. 28A and FIG. 28B is that, an Al—Si (silicon addedaluminum film) electrode is used as a surface electrode in FIG. 28A,while an Al—Li (lithium added aluminum film) electrode is used as asurface electrode in FIG. 28B. The result of FIG. 28B is the result ofthe measurement of the MOS construction shown in FIG. 29B. In FIG. 29B,the films are laminated with thermally-oxidized film in order to reducethe effect of difference in energy levels at the interface between thesilicon nitride film and the silicon substrate.

[0166] As can be seen from the graphs in FIGS. 28A and 28B, the C-Vcharacteristics before and after the BT stress test have similar shiftpattern, which indicates that there is no effect of lithium diffusion,that is, the silicon nitride film formed under the conditions of thetable 1 effectively serves as a blocking film.

[0167] As described, since the inorganic insulation layer used in thisinvention is extremely fine and has such high blocking effect againstmobile elements such as Na and Li, it can suppress diffusion of degassedcomponents from the planarizing film as well as suppress the diffusionof Li from the Al—Li electrode effectively. Taking advantage of theseeffects, a highly reliable display apparatus can be realized. Theinventors suppose that the inorganic insulation layer can be made finesince silicon clusters cannot easily contaminate the film, as a thinsilicon nitride film is formed on the surface of the single crystalsilicon target, then the silicon nitride film thus manufactured islaminated on the substrate.

[0168] Also, as the silicon nitride film is formed by the sputteringmethod at lower temperature i.e., from the ambient temperature to about200° C., the silicon nitride film which is used as a barrier filmaccording to the invention can be formed on the resin films, which isanother advantage over plasma CVD method. The above silicon nitride filmcan be used as a part of a gate insulation film when forming it bylaminating.

[0169] Embodiment

[0170] Embodiment 1

[0171] Next, the process of manufacturing the light emitting apparatusshown in FIG. 1 is described in detail with reference to the figures.

[0172] In FIG. 8A, the substrate 101 maybe one of a glass substrate, aquartz substrate or a ceramic substrate. The substrate 101 may comprisea silicon substrate, a metal substrate or a stainless substrate with aninsulation film formed thereon. A plastic substrate having heatresistance bearable to the processing temperature of the embodiment maybe used.

[0173] A first inorganic insulation layer 102 consisting of a insulationfilm such as a silicon oxide film, a silicon nitride film or a siliconoxynitride film (SiO_(x)N_(y)) is formed on the substrate 101. A typicalexample has two-layer construction, in which the first siliconoxynitride film of 50 nm thickness is formed using SiH₄, NH₃ and N₂O asa reaction gas, and the second silicon oxynitride film of 100 nmthickness is formed on the first film, using SiH₄ and N₂O as a reactiongas.

[0174] The semiconductor layer can be obtained by crystallizing theamorphous semiconductor film formed on the first inorganic insulationlayer 102. The amorphous semiconductor film is formed with thickness of30 to 60 nm, and crystallized by heating, or irradiating laser beams.There is no restriction on the material of the amorphous semiconductorfilm, however, silicon or silicon germanium (Si_(1-x)Ge_(x); 0<x<1.Representative value for x is 0.001 to 0.05) alloy may be preferablyused.

[0175] In a representative example, the amorphous silicon film of 54 nmthickness is formed by the plasma CVD method using SiH₄ gas. Incrystallization, a pulse oscillating or a continuous oscillating excimerlaser, or a YAG laser, a YVO₄ laser or a YLF laser which are doped withone of Cr, Nd, Er, Ho, Ce, Co, Ti or Tm can be used. When using one of aYAG laser, a YVO₄ laser or a YLF laser, the second harmonic to thefourth harmonic can be used. When using one of these lasers, the laserbeam irradiated from the laser oscillator can be linearly collected byan optical system to irradiate on the semiconductor film. The conditionof the crystallization can be selected by the operator appropriately.

[0176] For crystallization, certain metal element such as nickel whichcan serve as a catalyst for the crystallization of the semiconductor canbe added. An exemplary process of crystallization is; holding a solutioncontaining nickel on the amorphous silicon film, dehydrogenating (500°C. for one hour), crystallizing by furnace annealing at 550° C. for fourhours or gas heating rapid annealing at 740° C. for 180 seconds, thenirradiating the second harmonic of a continuous oscillating laserselected from an excimer laser, a YAG laser, a YVO₄ laser, or a YLFlaser, in order to improve the crystallization.

[0177] The resulting crystalline semiconductor film is etched in adesired form by photolithography using a photo mask (1) to formsemiconductor layers 103 to 107 separated like islands. FIG. 12 shows atop view of the pixel formation section on this point.

[0178] Also, after crystallization of the amorphous semiconductor film,the film can be doped with p-type impurity element in order to controlthreshold of the TFT. P-type impurity elements include the elementsbelonging to the Group 13 in the periodic table, such as boron (B),aluminum (Al) and garium (Ga).

[0179] Next, as shown in FIG. 8B, the gate insulation film 108 coveringthe semiconductor layers 103 to 107 separated like islands is formed.The gate insulation film 108 of 40 to 150 nm thickness is formed frominsulation film containing silicon by the plasma CVD method or thesputtering using inorganic insulation materials such as silicon oxide orsilicon oxynitride. This gate insulation layer can use insulation filmcontaining silicon as a single layer construction or a laminatedconstruction.

[0180] A first conductive film 10 of 30 nm thickness comprising tantalumnitride (TaN), and a second conductive film 11 of 400 nm thicknesscomprising tungsten (W) are laminated on the gate insulation film 108 inorder to form a gate electrode. Other conductive material for gateelectrode may be selected from Ta, W, Ti, Mo, Al, Cu, or an alloy or achemical compound having one of above elements as a main component.Also, a semiconductor film including a poly-crystalline silicon filmdoped with an impurity element such as phosphorous may be used.Furthermore, a combination of the first conductive film of a tantalumfilm (Ta) and the second conductive film of a W film, a combination ofthe first conductive film of a tantalum nitride (TaN) film and thesecond conductive film of a Al film, or a combination of the firstconductive film of a tantalum nitride (TaN) film, and the secondconductive film of Ti film may be also accepted.

[0181] Next, as shown in FIG. 8C, a mask 12 by which gate electrodepatterns are formed by photolithography is formed by using a photo mask(2). After that, the first etching is performed with dry-etching, forexample, ICP (Inductively Coupled Plasma) etching. There is norestriction on the etching gas, however, CF₄, Cl₂ and O₂ are used foretching of W and TaN. In the first etching, predetermined biasingvoltage is applied to the substrate to make inclination angle of 15 to50 degrees on the side surface of the formed electrode patterns 13 to17. The first etching reduces the thickness of the exposed region ofsurface of the insulation film by 10 to 30 nm.

[0182] Next, anisotropic etching is performed on the W film using SF₆,Cl₂ and O₂ as etching gases, and applying predetermined biasing voltageto the substrate, changing the first etching condition to the secondetching condition. The gate electrodes 110 to 113 and the wiring 109 ofan input terminal are thus formed. After that, the mask 12 is removed.The second etching further reduces the thickness of the exposed regionin the surface of the insulation layer by about 10 to 30 nm. FIG. 13shows a top view of the pixel formation section at this point.

[0183] After formation of the gate electrode, a first doping isperformed as shown in FIG. 9A to form first n-type impurity regions in18 to 22 on the semiconductor layer. These first n-type impurity regionsare formed in a self-aligned manner using the gate electrode as a mask.The doping condition can be set appropriately, using 5% PH₃ diluted withhydrogen, and injecting 6×10¹³/cm² dose at 50 kV.

[0184] Next, as shown in FIG. 9B, a mask 23 is formed by using aphoto-mask (3) and a second doping is performed by photolithography. Thesecond doping uses 5% PH₃ diluted with hydrogen, and injects 3×10¹⁵/cm²dose at 65 kV to form second n-type impurity regions 24, 25 and 27 andthird n-type impurity regions 26 and 28. The second n-type impurityregion 24 and the third n-type impurity region 26 formed in thesemiconductor layer 103 are formed in a self-aligned manner using thegate electrode as a mask. The second n-type impurity region 27 and thethird n-type impurity region 28 formed in the semiconductor layer 106are formed in a self-aligned manner using the gate electrode as a mask.In the semiconductor layer 105, the second n-type impurity region 25 isformed by the mask 23.

[0185] As shown in FIG. 9C, a mask 29 is formed by using a photo-mask(4), and a third doping is performed by photolithography. The thirddoping uses 5% B₂H₆ diluted with hydrogen, and injecting 2×10¹⁶/cm² doseat 80 kV to form a p-type impurity region 30 in the semiconductor layer104.

[0186] As the result of the above processes, the impurity regions havingeither n-type conductivity or p-type conductivity are formed on eachsemiconductor layer, respectively. As shown in FIG. 10A, in thesemiconductor layer 103, the second n-type impurity region 24 acts as asource or drain region, and the third n-type impurity region 26 acts asa LDD region. In the semiconductor layer 104, the p-type impurity region30 acts as a source or drain region. In the semiconductor layer 105, thesecond n-type impurity region 25 acts as a source or drain region, andthe first n-type impurity region 20 acts as a LDD region. In thesemiconductor layer 106, the second n-type impurity region 27 acts as asource or drain-region, and the third n-type impurity region 28 acts asa LDD region.

[0187] Next, the second inorganic insulation layer 114 covering almostall the surface is formed. The second inorganic insulation layer 114 of100 to 200 nm thickness is formed using the plasma CVD or thesputtering, with an inorganic insulation material containing silicon andhydrogen. The preferred example is an silicon oxynitride film of 150 nmthickness formed by the plasma CVD.

[0188] After formation of the second inorganic insulation layer 114,each impurity element added to each semiconductor layer is activated.Activation is performed by heating in a furnace anneal or a clean oven.The temperature is 400 to 700° C., typically, 410 to 500° C. of nitrogenatmosphere. The impurity regions may be activated by laser anneal, orrapid thermal anneal (RTA), as well.

[0189] Next, as shown in FIG. 10B, the first organic insulation layer115 of 0.5 to 1 μm is formed on the second inorganic insulation layer114. Thermosetting acrylic material can be used as the organicinsulation layer, which is spin-coated, then calcined at 250° C. to formplanarized film. On this film, the third inorganic insulation layer 116of 50 to 100 nm thickness is formed.

[0190] When forming the third inorganic insulation layer 116, thesubstrate having the second inorganic insulation layer 114 formedthereon is heated at 80 to 200° C. under reduced pressure fordehydration. An exemplary material suitable for the third inorganicinsulation layer 116 is silicon nitride formed by sputtering usingsilicon as a target.

[0191] Conditions for forming a film can be selected appropriately.Preferably, nitrogen (N₂) or mix of nitrogen and argon is applied assputtering gas by RF power for sputtering. The substrate may beprocessed in atmosphere temperature, without heating. An exemplaryprocess shows infrared absorption spectrum of the silicon nitride film(#001) formed by applying RF power (13.56 MHz) using silicon as atarget, and using only nitrogen gas for sputtering. The film is formedby using silicon target boron added by 1 to 2 Ωsq., applying 0.4 Pa, 800W RF power (13.56 MHz) and applying only nitrogen gas. The target has adiameter of 152.4 mm. The resultant silicon nitride film has oxygencontent of 20 atomic % or less, preferably 10 atomic % or less. Byreducing oxygen concentration, the film can be more fine and can improvetransmittance of light in short-wavelength range.

[0192] Next, as shown in FIG. 10C, a mask pattern is formed fromphoto-mask (5) by photolithography. A contact hole 30 and an opening 31of the input terminal are formed by using a photo-mask (5), forming maskpatterns by photolithography, and dry-etching. The conditions of thedry-etching are as follows; etching the third inorganic insulation layer116 and the second inorganic insulation layer 114 using CF₄, O₂ and He,then, etching the second inorganic insulation layer is performed and thegate insulation layer using CHF₃.

[0193] After that, as shown in FIG. 11A, wirings and pixel electrodesare formed using Al, Ti, Mo or W. A photo-mask (6) is used for formingwirings. For example, a laminated film of a Ti film of 50 to 250 nmthickness and an alloy film comprising Al and Ti of 300 to 500 nmthickness may be used. The wirings 117 to 125 are thus formed.

[0194] Next, as shown in FIG. 11B, the second organic insulation layer128 is formed. This layer is formed with an acrylic material similar tothe first organic insulation layer 115. Then, openings are formed on thewiring 123, the connection of the anode layer 310, and the inputterminal by using a photo-mask (7). The second organic insulation layer128 is formed so as to cover the end of the wiring 123, and its sidesurface has an inclination angle of 45 degree.

[0195] The organic insulation material is hygroscopic and occludesmoisture. In order to prevent the occlusion and release of moisture, afourth inorganic insulation layer 129 of 10 to 100 nm thickness isformed on the second organic insulation layer 128. The fourth inorganicinsulation layer 129 is formed of inorganic insulation materialconsisting of a nitride. The fourth inorganic insulation layer 129 isformed from a silicon nitride film manufactured by the sputtering. Theapplicable film is similar to that for the third inorganic insulationlayer 116. The fourth inorganic insulation layer 129 is formed intopredetermined patterns by using a photo-mask (8), and covers the uppersurface and the side surface of the second organic insulation layer 128,with a tapered end overlapping with the wiring 123. Thus, the fourthinorganic insulation layer 129 is formed at the input terminal so as tocover the side surface of the opening formed in the second organicinsulation layer 128, so that it prevents moisture from penetrating fromthis region.

[0196] Next, the cathode layer 126 is formed by using calcium fluorideor cesium fluoride as a material and depositing it by vacuum deposition.Then, the organic compound layer 130 containing light emitting materialis formed. The anode layer 131 is formed on the organic compound layercontaining light emitting material, by the sputtering or resistanceheating deposition. ITO can be used as the anode layer 131. Patterns onthese layers are formed by using a metal-mask (also called ashadow-mask). The anode layer 131 is the electrode to which commonpotential is applied, and extended to the connection 310 to contact tothe wiring 120. Also, ITO film 127 is formed on the wiring at the inputterminal.

[0197] Noble gas (typically argon) is used in sputtering method. Ions ofsputtering gas are not only accelerated by sheath electric field andclash with a target, but also are accelerated by weak sheath electricfield and implanted into the organic compound layer 130 containing alight emitting material under the anode. The noble gas preventsmolecules or atoms from displacing by positioning between lattices ofthe organic compound layers and improves stability of the organiccompounds. Further, the fifth inorganic insulation layer 132 formed onthe anode 131 is formed of silicon nitride or DLC film. The ions ofnoble gas (typically argon) are accelerated by weak sheath electricfield on the side of substrate and implanted into the organic compoundlayer 131 under the anode 131 passing through the anode. Then, an effectof improving stability of the organic compound can be obtained.

[0198] Then, seal patterns are formed, a sealing plate is adhered tomanufacture a light emitting apparatus shown in FIG. 1. According to theabove processes, a light emitting apparatus can be completed with eightphoto-masks.

[0199] Embodiment 2

[0200] Next, a light emitting apparatus having different structure thanthat of the embodiment 1 will be described with reference to FIG. 14.The processes from the beginning to the formation of the third inorganicinsulation layer 116 are same as those in the embodiment 1. Then, acontact hall and wirings 117 to 125 are formed.

[0201] Next, a third organic insulation layer 180 of about 1 μmthickness is formed of materials such as acrylic or polyimide. On thisthird organic insulation layer 180, a seventh inorganic insulation layer181 is formed with silicon nitride for the same reason as the embodiment1.

[0202] A contact hall connecting to the wiring 123 and a cathode layer126 are formed. A fourth organic insulation layer 182 is formed at theend of the cathode layer 126 and the recess of the contact hall. Thesurface of the fourth organic insulation layer 182 is covered with aneighth inorganic insulation layer 183. After that, an organic compoundlayer 130 containing light emitting material, an anode layer 131, sealpatterns 133 are formed, and a sealing plate is adhered to complete thelight emitting apparatus.

[0203] Embodiment 3

[0204] This embodiment has a different construction than that of theembodiment 1 for the pixel section, as illustrated in FIGS. 31 and 32.In this embodiment, the processes from the beginning to the formation ofthe third inorganic insulation layer 116 and wiring 123 on the thirdinorganic insulation layer 116 are same as FIG. 1.

[0205] As shown in FIG. 31A, a second organic insulation layer 180covering the end of the wiring 123 is formed of a photosensitive,negative-type acrylic resin. Thus, the end where the second organicinsulation layer 180 contacts with the wiring 123 has a inclined surfacehaving a curvature as shown in the figure, the shape of which can beexpressed by at least two curvatures R1 and R2. The center of the R1 islocated above the wiring, while that of the R2 is located below thewiring. This shape may vary slightly depending on the exposure, but thethickness of the film is 1.5 μm and the value for R1 and R2 is 0.2 to 2μm. The inclined surface has continuously varying curvatures.

[0206] Then, along the inclined surface having these smooth curvatures,a fourth inorganic insulation layer 129, a cathode layer 126, an organiccompound layer 130, an anode layer 131 and a fifth inorganic insulationlayer 132 are formed as shown in FIG. 31B. The shape of the section ofthis second organic insulation layer 180 has an effect of mitigatingstress (especially, a region where the wiring 123, the fourth inorganicinsulation layer 129 and the cathode layer 126 overlap), which makes itpossible to prevent the light emitting element from deteriorating fromthis end section. That is, this construction can prevent the progressivedeterioration which begins from the peripheral of the pixel then expandsto other region. In other words, a region not emitting light cannotexpand.

[0207]FIG. 32A shows an example wherein the second organic insulationlayer 181 is formed with a photosensitive positive-type acrylic resininstead of the photosensitive negative-type acrylic resin. In this case,the shape of the section at the end is different. The curvature radiusR3 is 0.2 to 2, with its center located below the wiring 123. Afterformation of the second organic insulation layer 181, a fourth inorganicinsulation layer 129, a cathode layer 126, an organic compound layer130, an anode layer 131 and fifth inorganic insulation layer 132 areformed along the inclined surface having curvatures as shown in FIG.32B. The similar effect can be obtained by this construction.

[0208] This embodiment can be implemented in combination with theembodiments 1 and 2.

[0209] Embodiment 4

[0210] For the embodiments 1 to 3, there is no restriction on theconstruction of the organic compound layer in the light emitting element309, so that, any known construction is applicable. The organic compoundlayer 130 has a light emitting layer, a positive holes injecting layer,an electrons injecting layer, a positive holes transferring layer and anelectrons transferring layer, and may have a construction wherein theselayers are laminated, or a construction wherein a part or all of thematerials forming these layers are mixed. Particularly, the lightemitting layer, the positive holes injecting layer, the electronsinjecting layer, the positive holes transferring layer and the electronstransferring layer are included. An basic EL element has a constructionwherein an anode, a light emitting layer, a cathode are laminated inthis order. Other possible construction includes a construction whereinthe layers are laminated in an order of an anode, a positive holesinjection layer, a light emitting layer and a cathode, or an order of ananode, a positive holes injecting layer, a light emitting layer, anelectrons transferring layer and a cathode form the top.

[0211] Typically, the light emitting layer is formed using organiccompound. However, it may be formed with charge injection transferringmaterial including organic compound or inorganic compound and a lightemitting material, it may contain one or more layers made of organiccompound selected from low molecular organic compounds, middle molecularorganic compounds, and polymer organic compounds, and the light emittinglayer may be combined with inorganic compound of an electrons injectiontransferring type or a positive holes injection transferring type. Themiddle molecular organic compounds refer to organic compounds which arenot sublimatic and have molecular numbers of 20 or less, or length ofcatenated molecules does not exceed 10 μm.

[0212] The applicable light emitting materials include metal complexsuch as tris-8-quinolinolatoaluminum complex or bis (benzoquinolinolato)beryllium complex as low molecular organic compounds, phenylanthracenederivative, tetraaryldiamine derivative and distyrylbenzen derivative.Using one of the above material as a host substance, coumarinderivative, DCM, quinacridone and rubrene may be applied. Other knownmaterials may be applicable as well. Polymer organic compounds includepolyparaphenylenevinylenes, polyparaphenylens, polythiophenes andpolyfluorenes, including, poly (p-phenylene vinylene): (PPV), poly(2,5-dialkoxy-1,4-phenylene vinylene):(RO-PPV), poly[2-2′-ethylhexoxy]-5-methoxy-1,4-phenylenevinylene]: (MEH-PPV), poly[2-(dialkoxyphenyl)-1,4,-phenylene vinylene]:(ROPh-PPV), poly(p-phenylene):(PPP), poly(2,5-dialkoxy-1,4-phenylene):(RO-PPP), poly(2,5-dihexoxy-1,4-phenylene), polythiophene:(PT), poly(3-alkylthiophene): (PAT), poly (3-hexylthiophene): (PHT),poly(3-cyclohexylthiophene):(PCHT),poly(3-cyclohexyl-4-methylthiophene):(PCHMT),poly(3,4-dicyclohexylthiophene):(PDCHT),poly[3-(4-octylphenyl)-thiophene]:(POPT),poly[3-(4-octylphenyl)-2,2-bithiophene]):(PTOPT), polyfluorene:(PF),poly (9,9-dialkylfluorene):(PDAF), poly (9,9-dioctylfluorene):(PDOF).

[0213] Inorganic compounds, such as diamond-like carbon (DLC), Si, Geand oxides and nitrides thereof, may be used for the charge injectiontransferring layer. The above materials may furthermore be added with P,B or N appropriately. Also, the charge injection transferring layer maybe oxides, nitrides or fluorides of alkali metals or alkali earthmetals, or compounds or alloys of the alkali metals or alkali earthmetals with at least Zn, Sn, V, Ru, Sm and In.

[0214] The listed materials are only examples. By using these materials,functional layers such as a positive holes injection transferring layer,a positive holes transferring layer, an electrons injection transferringlayer, an electrons transferring layer, a light emitting layer, anelectron block layer and a positive holes block layer can bemanufactured and laminated appropriately to form a light emittingelement. Also, a mixed layer or a mixed connection which combines theselayers may be formed, as well. The electroluminescence has two types oflight, i.e. a light which is emitted when the state moves back fromsinglet excited state to the ground state (fluorescence), and a lightwhich is emitted when the state moves back from triplet excited state tothe ground state (phosphorescence). The electroluminescence elementaccording to the invention can use either or both of these lights.

[0215] This embodiment can be implemented in combination withembodiments 1 to 3.

[0216] Embodiment 5

[0217] The cathode layer 126 and the anode layer 131 of the lightemitting element 309 in the embodiment 1 can be reversed. In this case,the layers are laminated in the order of the wiring 123, the anode layer126, the organic compound layer 130 and the cathode layer 131. Metalnitride (titanium nitride, for example) with a work function of 4 eV ormore, as well as ITO may be used for the anode layer 126. The cathodelayer 131 is formed from the lithium fluoride layer of 0.5 to 5 nmthickness and aluminum layer of 10 to 30 nm thickness. The aluminumlayer is formed as a translucent thin layer so that the light emittedfrom the organic compound layer 130 is irradiated through the cathodelayer 131.

[0218] This embodiment can be implemented in combination with theembodiments 1 to 4.

[0219] Embodiment 6

[0220] An embodiment of manufacturing process of the semiconductor layerto be applied to the TFT in the embodiment 1 or 2 will be described withreference to FIG. 18. In this embodiment, continuous oscillating laserbeams scan the amorphous silicon film formed on the insulation surfaceto crystallize the same.

[0221] A barrier layer 402 comprising a silicon oxynitride film of 100nm thickness is formed on a glass substrate 401, as shown in FIG. 18A.On the barrier layer 402, an amorphous silicon film 403 of 54 nmthickness is formed by the plasma CVD method.

[0222] The laser beams are continuous beams irradiated with continuousoscillation from a Nd:YVO₄ laser oscillator, and the second harmonic(532 nm) obtained by a wavelength conversion element is irradiated. Thecontinuous oscillating laser beams are collected in an oblong shape byan optical system, and by moving relative positions of the substrate 401the point from which the laser irradiate the beam 405, the amorphoussilicon film 403 is crystallized to form a crystalline silicon film 404.F20 cylindrical lens can be adopted as the optical system, whichtransforms the laser beam with a diameter of 2.5 mm into an oblong shapewith long axis of 2.5 mm and short axis of 20 μm on the irradiatedsurface.

[0223] Of course, other laser oscillator may equally be applicable. As acontinuous solid-state laser oscillator, a laser oscillator using acrystal such as YAG, YVO₄, YLF or YAlO₃, doped with Cr, Nd, Er, Ho, Ce,Co, Ti or Tm may be applicable.

[0224] When using the second harmonic (532 nm) of the Nd:YVO₄ laseroscillator, the laser beam of the wavelength is transmitted through theglass substrate 401 and the barrier layer 402. Therefore, the laser beam406 may be irradiated from the glass substrate 401 side, as shown inFIG. 18B.

[0225] Crystallization proceeds from the area on which the laser beam405 is irradiated, to form a crystalline silicon film 404. The laserbeam may be scanned in either one direction or backwards and forwards.When scanning back wards and forwards, the laser energy density may bechanged for each scanning to make gradual crystallization. The scanningmay have dehydrogenation effect as well, which is often necessary whenan amorphous silicon film is to be crystallized. In that case, the firstscanning may be performed at lower energy density, then, afterdehydrogenation, the second scanning may be performed at higher energydensity to complete the crystallization. Such process can also provide acrystalline semiconductor film in which crystal grains extend in thedirection of laser beam scanning. After these processes, semiconductorlayers are separated like islands, which can be applied to theembodiment 1.

[0226] The construction shown in this embodiment is only exemplary.Other laser oscillator, other optical system and combination thereof maybe applicable as long as similar effect can be obtained.

[0227] Embodiment 7

[0228] An embodiment of manufacturing process of the semiconductor layerto be applied to the TFT in the embodiment 1 or 2 will be described withreference to FIG. 19. In this embodiment, an amorphous silicon filmformed on the insulation surface is crystallized in advance, then,expanding the size of the crystal grains by continuous oscillating laserbeams.

[0229] As shown in FIG. 19A, a blocking layer 502 and an amorphoussilicon film 503 are formed on a glass substrate 501 as is in theembodiment 1. Nickel acetate 5 ppm solution is spin-coated to form acatalyst element containing layer 504 in order to add Ni as a metalelement to lower the crystallization temperature and promote thecrystallization.

[0230] The amorphous silicon film is crystallized by heating at 580° C.for four hours, as shown in FIG. 19B. Silicide is formed and diffused inthe amorphous silicon film by the action of Ni, and the crystal growssimultaneously. The resultant crystalline silicon film 506 consists ofbar-shaped or needle-shaped crystals, each of which grows in specificdirection when seen from a macroscopic viewpoint, thus the crystallinedirections are uniform.

[0231] As shown in FIG. 19C, scanning by continuous oscillating laserbeam 508 is performed to improve the quality of the crystallization ofthe crystalline silicon film 506. By irradiating the laser beam, thecrystalline silicon film melts and re-crystallize. In thisre-crystallization, the crystal grains extend in the scanning directionof the laser beam. It is possible to suppress deposition of crystallinegrains with different crystalline grains and formation of dislocations.After these processes, semiconductor layers are separated like islands,which can be applied to the embodiment 1.

[0232] Embodiment 8

[0233] An embodiment of manufacturing process of the semiconductor layerwhich can be applied to the TFT in the embodiment 1 or 2 will bedescribed with reference to FIG. 20.

[0234] As shown in FIG. 20A, a blocking layer 512 and an amorphoussilicon film 513 are formed on a glass substrate 511 as is in theembodiment 3. On the amorphous silicon film, a silicon oxide film of 100nm thickness is formed as a mask insulation film 514 by plasma CVD, andan opening 515 is provided. The nickel acetate 5 ppm solution isspin-coated in order to add Ni as a catalyst element. Ni solutioncontacts with the amorphous silicon film at the opening 515.

[0235] Next, as shown in FIG. 20B, the amorphous silicon film iscrystallized by heating at 580° C. for four hours. By the action of thecatalyst element, the crystal grows from the opening 515 in a directionparallel to the surface of the substrate. The resultant crystallinesilicon film 517 consists of bar-shaped or needle-shaped crystals, eachof which grows in specific direction when seen from a macroscopicviewpoint, thus the crystalline derections are uniform. Also, it isoriented in a specific direction.

[0236] After heating, the mask insulation film 514 is removed by etchingto obtain a crystalline silicon film 517 as shown in FIG. 20C. Afterthese processes, semiconductor layers are separated like islands, whichcan be applied to the embodiment 1.

[0237] Embodiment 9

[0238] In the embodiment 7 or 8, after the formation of the crystallinesilicon film 507 or 517, a process can be added to remove the catalystelement remaining in the film with concentration of 10¹⁹ atoms/cm³ ormore, by gettering.

[0239] As shown in FIG. 21, a barrier layer 509 comprising thin siliconoxide film is formed on the crystalline silicon film 507, then anamorphous silicon film added with argon or phosphorous of 1×10²⁰atoms/cm³ to 1×10²¹ atoms/cm³ is formed by the sputtering, as agettering site 510.

[0240] The Ni which is added as a catalyst element can be segregated tothe gettering site 510, by heating at 600° C. for 12 hours in a furnaceanneal, or by heating at 650 to 800° C. for 30 to 60 minutes with RTAusing lamp light or heated gas. This process reduces the concentrationof the catalyst element in the crystalline silicon film 507 to 10¹⁷atoms/cm³ or less.

[0241] The gettering under similar condition is effective for thecrystalline silicon film formed in the embodiment 2. The minute amountof the metal element contained in the crystalline silicon film formed byirradiating laser beams to the amorphous silicon film can be removed bythis gettering.

[0242] Embodiment 10

[0243]FIG. 23 shows an embodiment to make a module from an EL panel inwhich the pixel section and the driving circuit section are integrallyformed on the glass substrate, as shown in the embodiment 1. FIG. 23Aillustrates an EL module on which an IC containing a power supplycircuit for example is mounted on the EL panel.

[0244] In FIG. 23A, the EL panel 800 is provided with a pixel section803 having a light emitting element for each pixel, a scanning linedriving circuit 804 for selecting a pixel in the pixel section 803, anda signal line driving circuit 805 for supplying video signals to theselected pixel. Also, a print substrate 806 is provided with acontroller 801 and a power supply circuit 802. Various signals and powersupply voltage output from the controller 801 or a power supply circuit802 are supplied to the pixel section 803, the scanning line drivingcircuit 804 and the signal line driving circuit 805 of the EL panel 800via FPC 807.

[0245] The power supply voltage and various signals to the printsubstrate 806 are supplied via an interface (I/F) section 808 on which aplurality of input terminals are disposed. In this embodiment, the printsubstrate 806 is mounted on the EL panel 800 using FPC, but theinvention is not limited to this particular construction. The controller801 and the power supply circuit 802 may be mounted directly on the ELpanel 800 using COG (Chip on Glass) technique. In the print substrate806, noises may be introduced in the power supply voltage or the signalsdue to the capacity formed in the wirings or the resistance of thewirings itself, which may prevent sharp rising edge of a signal. Inorder to avoid this problem, the print substrate 806 may be providedwith elements such as a capacitor or a buffer, to prevent noises on thepower supply voltage or signals, and to keep sharp rising edge of thesignal.

[0246]FIG. 23B is a block diagram which shows a construction of theprint substrate 806. The various signals and the power supply voltagesupplied to the interface 808 are supplied to the controller 801 and thepower supply voltage 802. The controller 801 has an A/D converter 809, aPLL (phase locked loop) 810, a control signal generator 811 and SRAMs(Static Random Access Memory) 812 and 813. Although this embodiment usesSRAMs, SDRAMs or DRAMs (Dynamic Random Access Memory, provided that itcan read/write data at high speed) may be used as well.

[0247] The video signals supplied via the interface 808 are convertedfrom parallel form to serial form by the A/D converter 809, and inputinto the control signal generator 811, as video signals each of whichcorresponds to R, G, B colors, respectively. Based on the signalssupplied via the interface 808, the A/D converter 809 generates Hsyncsignals, Vsync signals, clock signal CLKs, and Volts alternating current[VAC], all of which are input into the control signal generator 811.

[0248] The phase locked loop 810 is able to make the phases of thefrequencies of the various signals supplied via the interface 808 to bematched to that of the operating frequency of the control signalgenerator 811. The operating frequency of the control signal generator811 is not always same as the frequency of the various signals suppliedvia the interface 808, so that the phase locked loop 810 adjusts theoperating frequency of the control signal generator 811 to make thefrequency synchronized with that of the signals. The video signal whichis input into the control signal generator 811 is temporarily writtenand stored in the SRAMs 812 and 813. From all of the video signal bitsstored in the SRAM 812, the control signal generator 811 reads the videosignal corresponding to the all pixels by one bit at a time, andsupplies the bit to the signal line driving circuit 805 of the EL panel800.

[0249] The control signal generator 811 supplies information related tothe period during which the light emitting element emits light for eachbit, to the scanning line driving circuit 804 of the EL panel 800. Thepower supply circuit 802 supplies the predetermined power supply voltageto the signal line driving circuit 805, the scanning line drivingcircuit 804 and the pixel section 803, of the EL panel 800.

[0250]FIG. 22 shows examples of electronic apparatuses in which theabove EL module may be incorporated.

[0251]FIG. 22A is an example of a television receiver in which the ELmodule is incorporated, comprising a casing 3001, a support 3002 and adisplay unit 3003. The TFT substrate manufactured according to theinvention is adopted in the display unit 3003 to complete the televisionreceiver.

[0252]FIG. 22B is an example of a video camera in which the EL module isincorporated, comprising a body 3011, a display unit 3012, a sound input3013, an operating switch 3014, a battery 3015 and an image receivingsection 3016. The TFT substrate manufactured according to the inventionis adopted in the display unit 3012 to complete the video camera.

[0253]FIG. 22C is an example of a notebook-type personal computer inwhich the EL module is incorporated, comprising a body 3021, a casing3022, a display unit 3023 and a keyboard 3024. The TFT substratemanufactured according to the invention is adopted in the display unit3023 to complete the personal computer.

[0254]FIG. 22D is an example of PDA (Personal Digital Assistant) inwhich the EL module is incorporated, comprising a body 3031, a stylus3032, a display unit 3033, an operating button 3034 and an externalinterface 3035. The TFT substrate manufactured according to theinvention is adopted in the display unit 3033 to complete the PDA.

[0255]FIG. 22E is an example of an car audio system in which the ELmodule is incorporated, comprising a body 3041, a display unit 3042 andoperating switches 3043 and 3044. The TFT substrate manufacturedaccording to the invention is adopted in the display unit 3042 tocomplete the car audio system.

[0256]FIG. 22F is an example of a digital camera in which the EL moduleis incorporated, comprising a body 3051, a display unit (A) 3052, aneyepiece 3053, an operating switch 3054, a display unit (B) 3055 and abattery 3056. The TFT substrates manufactured according to the inventionare adopted to the displays (A) 3052 and (B) 3055 to complete thedigital camera.

[0257]FIG. 22G is an example of a mobile telephone in which the Elmodule is incorporated, comprising a body 3061, a voice output section3062, a voice input section 3063, a display unit 3064, an operatingswitch 3065 and an antenna 3066. The TFT substrate manufacturedaccording to the invention is adopted to the display unit 3064 tocomplete the mobile telephone.

[0258] The application of the invention is not limited to theapparatuses shown in this figure. Instead, it can be adopted in avariety of electronics.

[0259] According to the invention, the semiconductor film, the gateinsulation film and the gate electrode, which are the main components ofa TFT, are surrounded by inorganic insulation materials over their uppersurfaces and under their lower surfaces to prevent contamination byalkali metals and organic materials. The inorganic insulation materialis selected from a group consisting of silicon nitride, siliconoxynitride, aluminum oxynitride, aluminum oxide and aluminum nitride.The organic light emitting element contains alkali metal in its part,and surrounded by inorganic insulation material to realize aconstruction which can prevent penetration of oxygen or moisture fromexternal world. The inorganic insulation material is selected from agroup consisting of silicon nitride, silicon oxynitride, aluminumoxynitride, aluminum oxide, aluminum nitride and DLC. This constructioncan improve the reliability of the light emitting apparatus.

What is claimed is:
 1. A light emitting device comprising: a thin filmtransistor over an insulating surface comprising: a semiconductor layer;a gate insulation film; and a gate electrode; a first inorganicinsulation layer under the semiconductor layer; a second inorganicinsulation layer over the gate electrode; a first organic insulationlayer over the second inorganic insulation layer; a third inorganicinsulation layer over the first organic insulation layer; a wiring layerextending over the third inorganic insulation layer; a second organicinsulation layer overlapping with an end of the wiring layer, the secondorganic insulation layer having an inclined surface with continuouslyvarying curvatures; a fourth inorganic insulation layer formed over anupper surface and a side surface of the second organic insulation layer,the fourth inorganic insulation layer having an opening over the wiringlayer; a cathode layer formed over the wiring layer, the cathode layerhaving an end overlapping with the fourth inorganic insulation layer; alight emitting layer comprising an organic material formed over thecathode layer and the fourth inorganic insulation layer; an anode layerformed over the light emitting layer comprising an organic material; anda fifth inorganic insulation layer formed over the anode layer, whereinthe light emitted from the light emitting material is visible throughthe fifth inorganic insulation layer and the anode, and wherein each ofthe third inorganic insulation layer and the fourth inorganic insulationlayer comprises a material selected from the group consisting of siliconnitride and aluminum nitride.
 2. A light emitting device comprising: apixel section over an insulating surface comprising a thin filmtransistor comprising: a semiconductor layer; a gate insulation film;and a gate electrode; a driving circuit section over the insulatingsurface comprising a thin film transistor comprising: a semiconductorlayer; a gate insulation film; and a gate electrode, a first inorganicinsulation layer under the semiconductor layer; a second inorganicinsulation layer over the gate electrode; a first organic insulationlayer over the second inorganic insulation layer; a third inorganicinsulation layer over the first organic insulation layer; a wiring layerextending over the third inorganic insulation layer; a second organicinsulation layer overlapping with an end of the wiring layer, the secondorganic insulation layer having an inclined surface with continuouslyvarying curvatures; a fourth inorganic insulation layer formed over theupper surface and the side surface of the second organic insulationlayer, the fourth inorganic insulation layer having an opening over thewiring layer; a cathode layer formed over the wiring layer, the cathodelayer having an end overlapping with the fourth inorganic insulationlayer; a light emitting layer comprising an organic material formed overthe cathode layer and the fourth inorganic insulation layer; an anodelayer formed over the light emitting layer comprising an organicmaterial; and a fifth inorganic insulation layer formed over the anodelayer; and a seal pattern over the fourth inorganic insulation layer,wherein the driving circuit section is formed in the peripheral regionof the pixel section, wherein the light emitted from the light emittingmaterial is visible through the fifth inorganic insulation layer,wherein each of the third inorganic insulation layer and the fourthinorganic insulation layer comprises a material selected from the groupconsisting of silicon nitride and aluminum nitride, and wherein the sealpattern is overlapped with the driving circuit section.
 3. The lightemitting device of claim 1, wherein the third inorganic insulation layerto the fifth inorganic insulation layer comprise silicon nitride formedby RF sputtering method.
 4. The light emitting device of claim 2,wherein each of the third inorganic insulation layer to the fifthinorganic insulation layer comprises silicon nitride formed by RFsputtering method.
 5. The light emitting device of claim 1, wherein thethird inorganic insulation layer to the fifth inorganic insulation layercomprise silicon nitride having etching rate of 9 nm/min or less.
 6. Thelight emitting device of claim 2, wherein the third inorganic insulationlayer to the fifth inorganic insulation layer comprise silicon nitridehaving etching rate of 9 nm/min or less.
 7. The light emitting device ofclaim 1, wherein the third inorganic insulation layer to the fifthinorganic insulation layer comprise silicon nitride having hydrogenconcentration of 1×10²¹ atoms/cm³ or less.
 8. The light emitting deviceof claim 2, wherein each of the third inorganic insulation layer to thefifth inorganic insulation layer comprises silicon nitride havinghydrogen concentration of 1×10²¹ atoms/cm³ or less.
 9. The lightemitting device of claim 1, wherein the third inorganic insulation layerto the fifth inorganic insulation layer comprise silicon nitride havingoxygen concentration of from 5×10¹⁸ to 5×10²¹ atoms/cm³.
 10. The lightemitting device of claim 2, wherein the third inorganic insulation layerto the fifth inorganic insulation layer comprise silicon nitride havingoxygen concentration of from 5×10¹⁸ to 5×10²¹ atoms/cm³.
 11. A lightemitting device comprising: a thin film transistor over an insulatingsurface comprising: a semiconductor layer; a gate insulation film; and agate electrode; a first inorganic insulation layer under thesemiconductor layer; a second inorganic insulation layer over the gateelectrode; a first organic insulation layer over the second inorganicinsulation layer; a third inorganic insulation layer over the firstorganic insulation layer; a wiring layer extending over the thirdinorganic insulation layer; a second organic insulation layeroverlapping with an end of the wiring layer, the second organicinsulation layer having an inclined surface with continuously varyingcurvatures; a fourth inorganic insulation layer formed over the uppersurface and the side surface of the second organic insulation layer, thefourth inorganic insulation layer having an opening over the wiringlayer; a cathode layer formed over the wiring layer, the cathode layerhaving an end overlapping with the fourth inorganic insulation layer; alight emitting layer comprising an organic material formed over thecathode layer and the fourth inorganic insulation layer; and an anodelayer formed over the light emitting layer comprising an organicmaterial, wherein each of the third inorganic insulation layer and thefourth inorganic insulation layer comprises a material selected from thegroup consisting of silicon nitride and aluminum nitride.
 12. The lightemitting device of claim 11, wherein each of the third inorganicinsulation layer to the fifth inorganic insulation layer comprisessilicon nitride having hydrogen concentration of 1×10²¹ atoms/cm³ orless.
 13. The light emitting device of claim 11, wherein the thirdinorganic insulation layer to the fifth inorganic insulation layercomprise silicon nitride having oxygen concentration of from 5×10¹⁸ to5×10²¹ atoms/cm³.
 14. A light emitting device comprising: a pixelsection over an insulating surface comprising a thin film transistorcomprising: a semiconductor layer; a gate insulation film; and a gateelectrode; a driving circuit section over the insulating surfacecomprising a thin film transistor comprising: a semiconductor layer; agate insulation film; and a gate electrode; a first inorganic insulationlayer under the semiconductor layer; a second inorganic insulation layerover the gate electrode; a first organic insulation layer over thesecond inorganic insulation layer; a third inorganic insulation layerover the first organic insulation layer; a wiring layer extending overthe third inorganic insulation layer; a second organic insulation layeroverlapping with an end of the wiring layer, the second organicinsulation layer having an inclined surface with continuously varyingcurvatures; a fourth inorganic insulation layer formed over the uppersurface and the side surface of the second organic insulation layer, thefourth inorganic insulation layer having an opening over the wiringlayer; a cathode layer formed over the wiring layer, the cathode layerhaving an end overlapping with the fourth inorganic insulation layer; alight emitting layer comprising an organic material formed over thecathode layer and the fourth inorganic insulation layer; an anode layerformed over the the light emitting layer comprising an organic material;and a seal pattern over the fourth inorganic insulation layer, whereinthe driving circuit section is formed in the peripheral region of thepixel section, and wherein each of the third inorganic insulation layerand the fourth inorganic insulation layer comprises a material selectedfrom the group consisting of silicon nitride and aluminum nitride. 15.The light emitting device according to claim 14, wherein the sealpattern is overlapped with the driving circuit section.
 16. The lightemitting device according to claim 14 further comprising a fifthinorganic insulation film over the anode layer.
 17. The light emittingdevice of claim 14, wherein each of the third inorganic insulation layerand the fourth inorganic insulation layer comprises silicon nitridehaving hydrogen concentration of 1×10²¹ atoms/cm³ or less.
 18. The lightemitting device of claim 15, wherein each of the third inorganicinsulation layer and the fourth inorganic insulation layer comprisessilicon nitride having hydrogen concentration of 1×10²¹ atoms/cm³ orless.
 19. The light emitting device of claim 16, wherein each of thethird inorganic insulation layer to the fifth inorganic insulation layercomprises silicon nitride having hydrogen concentration of 1×10²¹atoms/cm³ or less.
 20. The light emitting device of claim 14, whereinthe third inorganic insulation layer and the fourth inorganic insulationlayer comprise silicon nitride having oxygen concentration of from5×10¹⁸ to 5×10²¹ atoms/cm³.
 21. The light emitting device of claim 15,wherein the third inorganic insulation layer and the fourth inorganicinsulation layer comprise silicon nitride having oxygen concentration offrom 5×10¹⁸ to 5×10²¹ atoms/cm³.
 22. The light emitting device of claim16, wherein the third inorganic insulation layer to the fifth inorganicinsulation layer comprise silicon nitride having oxygen concentration offrom 5×10¹⁸ to 5×10²¹ atoms/cm³.
 23. A light emitting device comprising:a pixel section over an insulating surface comprising: a thin filmtransistor comprising: a semiconductor layer; a gate insulation film;and a gate electrode; a light emitting element comprising an organiccompound layer comprising light emitting material between an anode layerand a cathode layer; a driving circuit section over the insulatingsurface comprising a thin film transistor comprising: a semiconductorlayer; a gate insulation film; and a gate electrode; a barrier layerformed from an organic insulation layer over the pixel section and thedriving circuit section; an inorganic insulation layer comprisingsilicon nitride or aluminum nitride over the upper surface and the sidesurface of the barrier layer; and a seal pattern over the inorganicinsulation layer, wherein the driving circuit section is formed in theperipheral region of the pixel section, wherein the seal pattern isoverlapped with the driving circuit section, and wherein a connectionbetween the anode layer and the wiring formed under the anode layer isprovided inside of the seal pattern.
 24. A light emitting devicecomprising: a pixel section over an insulating surface comprising: afirst thin film transistor comprising: a semiconductor layer; a gateinsulation film; and a gate electrode; and a light emitting elementcomprising an organic compound layer comprising light emitting materialbetween an anode layer and a cathode layer; a driving circuit sectionover the insulating surface comprising a second thin film transistorcomprising: a semiconductor layer; a gate insulation film; and a gateelectrode; a barrier layer formed from an organic insulation layer overthe pixel section and the driving circuit section; an inorganicinsulation layer comprising silicon nitride or aluminum nitride over theupper surface and the side surface of the barrier layer; and a sealpattern over the inorganic insulation layer, wherein the driving circuitsection is formed in the peripheral region of the pixel section, whereinthe first thin film transistor is formed inside of the seal pattern,wherein some or all of the second thin film transistors overlap with theseal pattern, and wherein a connection between the anode layer and thewiring formed under the anode layer is provided inside of the sealpattern.
 25. A light emitting device comprising: a pixel section over aninsulating surface comprising: a thin film transistor comprising: asemiconductor layer; a gate insulation film; and a gate electrode; alight emitting element comprising an organic compound layer comprisinglight emitting material between an anode layer and a cathode layer; adriving circuit section over the insulating surface comprising a thinfilm transistor comprising: a semiconductor layer; a gate insulationfilm; and a gate electrode; a barrier layer formed from an organicinsulation layer over the pixel section and the driving circuit section;an inorganic insulation layer comprising silicon nitride or aluminumnitride over the upper surface and the side surface of the barrierlayer; and a seal pattern over the inorganic insulation layer, whereinthe driving circuit section is formed in the peripheral region of thepixel section, and wherein a connection between the anode layer and thewiring formed under the anode layer is provided inside of the sealpattern.
 26. The light emitting device of claim 23, wherein theinorganic insulation layer comprises silicon nitride formed by RFsputtering method.
 27. The light emitting device of claim 24, whereinthe inorganic insulation layer comprises silicon nitride formed by RFsputtering method.
 28. The light emitting device of claim 23, whereineach of the third inorganic insulation layer to the fifth inorganicinsulation layer comprises silicon nitride having etching rate of 9nm/min or less.
 29. The light emitting device of claim 24, wherein eachof the third inorganic insulation layer to the fifth inorganicinsulation layer comprises silicon nitride having etching rate of 9nm/min or less.
 30. The light emitting device of claim 23, wherein eachof the third inorganic insulation layer to the fifth inorganicinsulation layer comprises silicon nitride having hydrogen concentrationof 1×10²¹ atoms/cm³ or less.
 31. The light emitting device of claim 24,wherein each of the third inorganic insulation layer to the fifthinorganic insulation layer comprises silicon nitride having hydrogenconcentration of 1×10²¹ atoms/cm³ or less.
 32. The light emitting deviceof claim 25, wherein each of the third inorganic insulation layer to thefifth inorganic insulation layer comprises silicon nitride havinghydrogen concentration of 1×10²¹ atoms/cm³ or less.
 33. The lightemitting device of claim 23, wherein each of the third inorganicinsulation layer to the fifth inorganic insulation layer comprisessilicon nitride having oxygen concentration from 5×10¹⁸ to 5×10²¹atoms/cm³.
 34. The light emitting device of claim 24, wherein each ofthe third inorganic insulation layer to the fifth inorganic insulationlayer comprises silicon nitride having oxygen concentration from 5×10¹⁸to 5×10²¹ atoms/cm³.
 35. The light emitting device of claim 25, whereineach of the third inorganic insulation layer to the fifth inorganicinsulation layer comprises silicon nitride having oxygen concentrationfrom 5×10¹⁸ to 5×10²¹ atoms/cm³.
 36. A method for manufacturing a lightemitting device comprising a pixel section comprising a thin filmtransistor comprising a semiconductor layer, a gate insulation film anda gate electrode, and a light emitting element comprising an a lightemitting layer comprising an organic material between an anode layer anda cathode layer, and a driving circuit section comprising a thin filmtransistor comprising a semiconductor layer, a gate insulation film anda gate electrode, the driving circuit section being formed in theperipheral region of the pixel section, comprising steps of: forming afirst inorganic insulation layer over an insulating surface; forming asemiconductor layer comprising crystalline silicon over the firstinorganic insulation layer; forming a gate insulation film over thesemiconductor layer; forming a gate electrode over the gate insulationfilm; forming a second inorganic insulation layer over the gateelectrode; forming a first organic insulation layer over the secondinorganic insulation layer; forming a third inorganic insulation layerover the second organic insulation layer; forming a wiring layer overthe third inorganic insulation layer; forming a second organicinsulation layer overlapping with an end of the wiring layer, the secondorganic insulation layer having an inclined portion; forming a fourthinorganic insulation layer over the upper surface and the side surfaceof the second organic insulation layer, the fourth inorganic insulationlayer having an opening over the wiring layer; forming a cathode layerover the wiring layer, the cathode layer having an end overlapping withthe fourth inorganic insulation layer; forming a light emitting layercomprising an organic material over the cathode layer and the fourthinorganic insulation layer; and forming an anode layer over the lightemitting layer comprising an organic material, wherein each of the thirdinorganic insulation layer and the fourth inorganic insulation layercomprises a material selected from the group consisting of siliconnitride and aluminum nitride formed by RF sputtering method.
 37. Amethod for manufacturing a light emitting device comprising a pixelsection comprising a thin film transistor comprising a semiconductorlayer, a gate insulation film and a gate electrode, and a light emittingelement comprising a light emitting layer comprising an organic materialbetween an anode layer and a cathode layer, and a driving circuitsection comprising a thin film transistor comprising a semiconductorlayer, a gate insulation film and a gate electrode, the driving circuitsection being formed in the peripheral region of the pixel section,comprising steps of: forming a first inorganic insulation layer over aninsulating surface; forming a semiconductor layer comprising crystallinesilicon over the first inorganic insulation layer; forming a gateinsulation film over the semiconductor layer and a gate electrode overthe gate insulation film; forming a second inorganic insulation layerover the gate electrode; forming a first organic insulation layer overthe second inorganic insulation layer; forming a third inorganicinsulation layer over the first organic insulation layer; forming awiring layer over the third inorganic insulation layer; forming a secondorganic insulation layer overlapping with an end of the wiring layer,the second organic insulation layer having an inclination angle of 35 to45 degrees; forming a fourth inorganic insulation layer over the uppersurface and the side surface of the second organic insulation layer, thefourth inorganic insulation layer having an opening over the wiringlayer; forming a cathode layer over the wiring layer and having an endoverlapping with the fourth inorganic insulation layer; forming a lightemitting layer comprising an organic material over the cathode layer andthe fourth inorganic insulation layer; forming an anode layer over thelight emitting layer comprising an organic material; forming a sealpattern over the fourth insulation layer at a position in which the sealpattern is overlapped with the driving circuit section; and adhering asealing plate in alignment with the seal pattern, wherein each of thethird inorganic insulation layer and the fourth inorganic insulationlayer comprises a material selected from the group consisting of siliconnitride and aluminum nitride formed by RF sputtering method.
 38. Themethod for manufacturing the light emitting device of the claim 36,wherein each of the third inorganic insulation layer and the fourthinorganic insulation layer comprises silicon nitride formed by RFsputtering method using silicon as a target, and only nitrogen as asputtering gas.
 39. The method for manufacturing the light emittingdevice of the claim 37, wherein each of the third inorganic insulationlayer and the fourth inorganic insulation layer comprises siliconnitride formed by RF sputtering method using silicon as a target, andonly nitrogen as a sputtering gas.
 40. The method for manufacturing thelight emitting device of the claim 36, wherein each of the thirdinorganic insulation layer and the fourth inorganic insulation layer isformed by sputtering using a turbo molecular pump or a cryopump, withback-pressure of 1×10⁻³ Pa or less, and sputtering a single crystalsilicon target with N₂ gas or mixture of N₂ and noble gas.
 41. Themethod for manufacturing the light emitting device of the claim 37,wherein each of the third inorganic insulation layer and the fourthinorganic insulation layer is formed by sputtering using a turbomolecular pump or a cryopump, with back-pressure of 1×10⁻³ Pa or less,and sputtering a single crystal silicon target with N₂ gas or mixture ofN₂ and noble gas.
 42. The method for manufacturing the light emittingdevice of the claim 36, wherein the third inorganic insulation layer isformed after the formation of the first organic insulation layer, byheating and dehydrating under reduced pressure, while the reducedpressure is kept.
 43. The method for manufacturing the light emittingdevice of the claim 37, wherein the third inorganic insulation layer isformed after the formation of the first organic insulation layer, byheating and dehydrating under reduced pressure, while the reducedpressure is kept.
 44. The method for manufacturing the light emittingdevice of the claim 36, wherein the fourth inorganic insulation layer isformed after the formation of the second organic insulation layer, byheating and dehydrating under reduced pressure, while the reducedpressure is kept.
 45. The method for manufacturing the light emittingdevice of the claim 37, wherein the fourth inorganic insulation layer isformed after the formation of the second organic insulation layer, byheating and dehydrating under reduced pressure, while the reducedpressure is kept.
 46. The method for manufacturing the light emittingdevice according to claim 36 further comprising a step of forming afifth inorganic insulation layer over the anode layer after forming theanode layer.
 47. The method for manufacturing the light emitting deviceaccording to claim 37 further comprising a step of forming a fifthinorganic insulation layer over the anode layer after forming the anodelayer.
 48. A light emitting device comprising: a thin film transistorover an insulating surface comprising: a semiconductor layer; a gateinsulation film; and a gate electrode; a first inorganic insulationlayer under the semiconductor layer; a second inorganic insulation layerover the gate electrode; a first organic insulation layer over thesecond inorganic insulation layer; a third inorganic insulation layerover the first organic insulation layer; a wiring layer extending overthe third inorganic insulation layer; a second organic insulation layeroverlapping with an end of the wiring layer, the second organicinsulation layer having an inclined surface with continuously varyingcurvatures; a fourth inorganic insulation layer formed over an uppersurface and a side surface of the second organic insulation layer, thefourth inorganic insulation layer having an opening over the wiringlayer; and a light emitting element over the fourth inorganic insulationlayer comprising: a cathode layer; an anode layer; and a light emittinglayer comprising an organic material between the cathode layer and theanode layer, wherein each of the third inorganic insulation layer andthe fourth inorganic insulation layer comprises a material selected fromthe group consisting of silicon nitride and aluminum nitride.
 49. Alight emitting device comprising: a thin film transistor over aninsulating surface comprising: a semiconductor layer; a gate insulationfilm; and a gate electrode; a first inorganic insulation layer under thesemiconductor layer; a second inorganic insulation layer over the gateelectrode; a first organic insulation layer over the second inorganicinsulation layer; a third inorganic insulation layer over the firstorganic insulation layer; a wiring layer extending over the thirdinorganic insulation layer; a second organic insulation layeroverlapping with an end of the wiring layer, the second organicinsulation layer having an inclined surface with continuously varyingcurvatures; a fourth inorganic insulation layer formed over an uppersurface and a side surface of the second organic insulation layer, thefourth inorganic insulation layer having an opening over the wiringlayer; a light emitting element over the fourth inorganic insulationlayer comprising: a cathode layer; an anode layer; and a light emittinglayer comprising an organic material between the cathode layer and theanode layer; and a fifth inorganic insulation layer over the lightemitting element, wherein the light emitted from the light emittingmaterial is visible through the fifth inorganic insulation layer and theanode, and wherein each of the third inorganic insulation layer and thefourth inorganic insulation layer comprises a material selected from thegroup consisting of silicon nitride and aluminum nitride.
 50. A lightemitting device comprising: a pixel section over an insulating surfacecomprising a thin film transistor comprising: a semiconductor layer; agate insulation film; and a gate electrode; a driving circuit sectionover the insulating surface comprising a thin film transistorcomprising: a semiconductor layer; a gate insulation film; and a gateelectrode, a first inorganic insulation layer under the semiconductorlayer; a second inorganic insulation layer over the gate electrode; afirst organic insulation layer over the second inorganic insulationlayer; a third inorganic insulation layer over the first organicinsulation layer; a wiring layer extending over the third inorganicinsulation layer; a second organic insulation layer overlapping with anend of the wiring layer, the second organic insulation layer having aninclined surface with continuously varying curvatures; a fourthinorganic insulation layer formed over the upper surface and the sidesurface of the second organic insulation layer, the fourth inorganicinsulation layer having an opening over the wiring layer; a lightemitting element over the fourth inorganic insulation layer comprising:a cathode layer; an anode layer; and a light emitting layer comprisingan organic material between the cathode layer and the anode layer; and aseal pattern over the fourth inorganic insulation layer, wherein thedriving circuit section is formed in the peripheral region of the pixelsection, and wherein each of the third inorganic insulation layer andthe fourth inorganic insulation layer comprises a material selected fromthe group consisting of silicon nitride and aluminum nitride.
 51. Alight emitting device comprising: a pixel section over an insulatingsurface comprising a thin film transistor comprising: a semiconductorlayer; a gate insulation film; and a gate electrode; a driving circuitsection over the insulating surface comprising a thin film transistorcomprising: a semiconductor layer; a gate insulation film; and a gateelectrode, a first inorganic insulation layer under the semiconductorlayer; a second inorganic insulation layer over the gate electrode; afirst organic insulation layer over the second inorganic insulationlayer; a third inorganic insulation layer over the first organicinsulation layer; a wiring layer extending over the third inorganicinsulation layer; a second organic insulation layer overlapping with anend of the wiring layer, the second organic insulation layer having aninclined surface with continuously varying curvatures; a fourthinorganic insulation layer formed over the upper surface and the sidesurface of the second organic insulation layer, the fourth inorganicinsulation layer having an opening over the wiring layer; a lightemitting element over the fourth inorganic insulation layer comprising:a cathode layer; an anode layer; and a light emitting layer comprisingan organic material between the cathode layer and the anode layer; afifth inorganic insulation layer over the light emitting element; and aseal pattern over the fourth inorganic insulation layer, wherein thedriving circuit section is formed in the peripheral region of the pixelsection, wherein the light emitted from the light emitting material isvisible through the fifth inorganic insulation layer, and wherein eachof the third inorganic insulation layer and the fourth inorganicinsulation layer comprises a material selected from the group consistingof silicon nitride and aluminum nitride.
 52. The light emitting deviceaccording to claim 48 further comprising a fifth inorganic insulationlayer over the light emitting element.
 53. The light emitting deviceaccording to claim 50 further comprising a fifth inorganic insulationlayer over the light emitting element.
 54. The light emitting deviceaccording to claim 50, wherein the seal pattern is overlapped with thedriving circuit section.
 55. The light emitting device according toclaim 51, wherein the seal pattern is overlapped with the drivingcircuit section.
 56. The light emitting device according to claim 48,wherein each of the third inorganic insulation layer and the fourthinorganic insulation layer comprises silicon nitride having hydrogenconcentration of 1×10²¹ atoms/cm³ or less.
 57. The light emitting deviceaccording to claim 49, wherein each of the third inorganic insulationlayer and the fourth inorganic insulation layer comprises siliconnitride having hydrogen concentration of 1×10² atoms/cm³ or less. 58.The light emitting device according to claim 50, wherein each of thethird inorganic insulation layer and the fourth inorganic insulationlayer comprises silicon nitride having hydrogen concentration of 1×10²atoms/cm³ or less.
 59. The light emitting device according to claim 51,wherein each of the third inorganic insulation layer and the fourthinorganic insulation layer comprises silicon nitride having hydrogenconcentration of 1×10² atoms/cm³ or less.
 60. The light emitting deviceaccording to claim 48, wherein each of the third inorganic insulationlayer and the fourth inorganic insulation layer comprises siliconnitride having hydrogen concentration of 1×10²¹ atoms/cm³ or less. 61.The light emitting device according to claim 49, wherein the thirdinorganic insulation layer and the fourth inorganic insulation layercomprise silicon nitride having oxygen concentration of from 5×10¹⁸ to5×10²¹ atoms/cm³.
 62. The light emitting device according to claim 50,wherein the third inorganic insulation layer and the fourth inorganicinsulation layer comprise silicon nitride having oxygen concentration offrom 5×10¹⁸ to 5×10²¹ atoms/cm³.
 63. The light emitting device accordingto claim 51, wherein the third inorganic insulation layer and the fourthinorganic insulation layer comprise silicon nitride having oxygenconcentration of from 5×10¹⁸ to 5×10²¹ atoms/cm³.
 64. The light emittingdevice according to claim 52, wherein the fifth inorganic insulationlayer comprises a material selected from the group consisting of siliconnitride and aluminum nitride.
 65. The light emitting device according toclaim 53, wherein the fifth inorganic insulation layer comprises amaterial selected from the group consisting of silicon nitride andaluminum nitride.
 66. The light emitting device according to claim 52wherein the fifth inorganic insulation layer comprises silicon nitridehaving hydrogen concentration of 1×10²¹ atoms/cm³ or less.
 67. The lightemitting device according to claim 53 wherein the fifth inorganicinsulation layer comprises silicon nitride having hydrogen concentrationof 1×10²¹ atoms/cm³ or less.
 68. The light emitting device according toclaim 52, wherein the fifth inorganic insulation layer comprises siliconnitride having oxygen concentration of from 5×10¹⁸ to 5×10²¹ atoms/cm³.69. The light emitting device according to claim 53, wherein the fifthinorganic insulation layer comprises silicon nitride having oxygenconcentration of from 5×10¹⁸ to 5×10²¹ atoms/cm³.